mypy: Address issues with top-level files

Address issues in all files in the 'openstack' directory as well as the
'openstack/common', 'openstack/config' and 'openstack/test' directories.
With this done, we can start introducing mypy iteratively.

Note that we disable type hints in Sphinx. This is necessary because
Sphinx apparently can't tell the difference between 'Type' from 'typing'
and 'Type' from 'openstack.block_storage.v[23].Type', which causes a
build warning. This is okay since typing makes docs too noisy anyway.

Change-Id: Ia91c5da779b5b68c408dfc934a21d77e9ca2f550
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

doc/source/conf.py

@@ -60,7 +60,13 @@ add_module_names = True
 # The name of the Pygments (syntax highlighting) style to use.
 pygments_style = 'native'
 
-autodoc_member_order = "bysource"
+autodoc_member_order = 'bysource'
+
+# Include both the class and __init__ docstrings when describing the class
+autoclass_content = 'both'
+
+# Don't document type hints as they're too noisy
+autodoc_typehints = 'none'
 
 # Locations to exclude when looking for source files.
 exclude_patterns = []
@@ -70,8 +76,7 @@ exclude_patterns = []
 # Don't let openstackdocstheme insert TOCs automatically.
 theme_include_auto_toc = False
 
-# Output file base name for HTML help builder.
+# -- Options for LaTeX output ---------------------------------------------
-htmlhelp_basename = 'openstacksdkdoc'
 
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title, author, documentclass
@@ -91,6 +96,3 @@ latex_elements = {'maxlistdepth': 10}
 
 # Disable usage of xindy https://bugzilla.redhat.com/show_bug.cgi?id=1643664
 latex_use_xindy = False
-
-# Include both the class and __init__ docstrings when describing the class
-autoclass_content = "both"

openstack/common/metadata.py

@@ -9,12 +9,17 @@
 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 # License for the specific language governing permissions and limitations
 # under the License.
+
 from openstack import exceptions
 from openstack import resource
 from openstack import utils
 
 
 class MetadataMixin:
+    id: resource.Body
+    base_path: str
+    _body: resource._ComponentManager
+
     #: *Type: list of tag strings*
     metadata = resource.Body('metadata', type=dict)
 

openstack/common/quota_set.py

@@ -9,6 +9,9 @@
 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 # License for the specific language governing permissions and limitations
 # under the License.
+
+import typing as ty
+
 from openstack import exceptions
 from openstack import resource
 
@@ -88,7 +91,7 @@ class QuotaSet(resource.Resource):
                 body.pop("self", None)
 
                 # Process body_attrs to strip usage and reservation out
-                normalized_attrs = dict(
+                normalized_attrs: ty.Dict[str, ty.Any] = dict(
                     reservation={},
                     usage={},
                 )

openstack/common/tag.py

@@ -9,12 +9,21 @@
 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 # License for the specific language governing permissions and limitations
 # under the License.
+
 from openstack import exceptions
 from openstack import resource
 from openstack import utils
 
 
 class TagMixin:
+    id: resource.Body
+    base_path: str
+    _body: resource._ComponentManager
+
+    @classmethod
+    def _get_session(cls, session):
+        ...
+
     _tag_query_parameters = {
         'tags': 'tags',
         'any_tags': 'tags-any',

openstack/config/cloud_region.py

@@ -14,6 +14,7 @@
 
 import copy
 import os.path
+import typing as ty
 import urllib
 import warnings
 
@@ -195,7 +196,7 @@ def from_conf(conf, session=None, service_types=None, **kwargs):
                     ),
                 )
                 continue
-        opt_dict = {}
+        opt_dict: ty.Dict[str, str] = {}
         # Populate opt_dict with (appropriately processed) Adapter conf opts
         try:
             ks_load_adap.process_conf_options(conf[project_name], opt_dict)

openstack/config/loader.py

@@ -21,6 +21,7 @@ import json
 import os
 import re
 import sys
+import typing as ty
 import warnings
 
 import appdirs
@@ -129,7 +130,7 @@ def _fix_argv(argv):
                 argv[index] = "=".join(split_args)
             # Save both for later so we can throw an error about dupes
             processed[new].add(orig)
-    overlap = []
+    overlap: ty.List[str] = []
     for new, old in processed.items():
         if len(old) > 1:
             overlap.extend(old)
@@ -297,8 +298,8 @@ class OpenStackConfig:
         self._cache_expiration_time = 0
         self._cache_path = CACHE_PATH
         self._cache_class = 'dogpile.cache.null'
-        self._cache_arguments = {}
+        self._cache_arguments: ty.Dict[str, ty.Any] = {}
-        self._cache_expirations = {}
+        self._cache_expirations: ty.Dict[str, int] = {}
         self._influxdb_config = {}
         if 'cache' in self.cloud_config:
             cache_settings = _util.normalize_keys(self.cloud_config['cache'])
@@ -514,8 +515,8 @@ class OpenStackConfig:
             return self._expand_regions(regions)
         else:
             # crappit. we don't have a region defined.
-            new_cloud = dict()
+            new_cloud: ty.Dict[str, ty.Any] = {}
-            our_cloud = self.cloud_config['clouds'].get(cloud, dict())
+            our_cloud = self.cloud_config['clouds'].get(cloud, {})
             self._expand_vendor_profile(cloud, new_cloud, our_cloud)
             if 'regions' in new_cloud and new_cloud['regions']:
                 return self._expand_regions(new_cloud['regions'])

openstack/config/vendors/__init__.py

@@ -15,6 +15,7 @@
 import glob
 import json
 import os
+import typing as ty
 import urllib
 
 import requests
@@ -24,7 +25,7 @@ from openstack.config import _util
 from openstack import exceptions
 
 _VENDORS_PATH = os.path.dirname(os.path.realpath(__file__))
-_VENDOR_DEFAULTS = {}
+_VENDOR_DEFAULTS: ty.Dict[str, ty.Dict] = {}
 _WELL_KNOWN_PATH = "{scheme}://{netloc}/.well-known/openstack/api"
 
 

openstack/connection.py

@@ -209,7 +209,7 @@ try:
     import importlib.metadata as importlib_metadata
 except ImportError:
     # For everyone else
-    import importlib_metadata
+    import importlib_metadata  # type: ignore
 import keystoneauth1.exceptions
 import requestsexceptions
 

openstack/exceptions.py

@@ -18,6 +18,7 @@ Exception definitions.
 
 import json
 import re
+import typing as ty
 
 from requests import exceptions as _rex
 
@@ -214,6 +215,7 @@ def raise_from_response(response, error_message=None):
     if response.status_code < 400:
         return
 
+    cls: ty.Type[SDKException]
     if response.status_code == 400:
         cls = BadRequestException
     elif response.status_code == 403:
@@ -251,6 +253,7 @@ def raise_from_response(response, error_message=None):
             message = re.sub(r'<.+?>', '', line.strip())
             if message not in messages:
                 messages.append(message)
+
         # Return joined string separated by colons.
         details = ': '.join(messages)
 

openstack/network/v2/_proxy.py

@@ -9,10 +9,8 @@
 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 # License for the specific language governing permissions and limitations
 # under the License.
-from typing import Generic
+
-from typing import Optional
+import typing as ty
-from typing import Type
-from typing import TypeVar
 
 from openstack import exceptions
 from openstack.network.v2 import address_group as _address_group
@@ -93,11 +91,10 @@ from openstack.network.v2 import (
 )
 from openstack.network.v2 import vpn_service as _vpn_service
 from openstack import proxy
-
+from openstack import resource
-T = TypeVar('T')
 
 
-class Proxy(proxy.Proxy, Generic[T]):
+class Proxy(proxy.Proxy):
     _resource_registry = {
         "address_group": _address_group.AddressGroup,
         "address_scope": _address_scope.AddressScope,
@@ -179,24 +176,24 @@ class Proxy(proxy.Proxy, Generic[T]):
     @proxy._check_resource(strict=False)
     def _update(
         self,
-        resource_type: Type[T],
+        resource_type: ty.Type[resource.Resource],
         value,
         base_path=None,
         if_revision=None,
         **attrs,
-    ) -> T:
+    ) -> resource.Resource:
         res = self._get_resource(resource_type, value, **attrs)
         return res.commit(self, base_path=base_path, if_revision=if_revision)
 
     @proxy._check_resource(strict=False)
     def _delete(
         self,
-        resource_type: Type[T],
+        resource_type: ty.Type[resource.Resource],
         value,
         ignore_missing=True,
         if_revision=None,
         **attrs,
-    ) -> Optional[T]:
+    ) -> ty.Optional[resource.Resource]:
         res = self._get_resource(resource_type, value, **attrs)
 
         try:

openstack/network/v2/port.py

@@ -9,7 +9,8 @@
 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 # License for the specific language governing permissions and limitations
 # under the License.
-from typing import List
+
+import typing as ty
 
 from openstack.common import tag
 from openstack.network.v2 import _base
@@ -58,7 +59,7 @@ class Port(_base.NetworkResource, tag.TagMixin):
     # Properties
     #: Allowed address pairs list. Dictionary key ``ip_address`` is required
     #: and key ``mac_address`` is optional.
-    allowed_address_pairs: List[dict] = resource.Body(
+    allowed_address_pairs: ty.List[dict] = resource.Body(
         'allowed_address_pairs', type=list
     )
     #: The ID of the host where the port is allocated. In some cases,

openstack/proxy.py

@@ -11,11 +11,7 @@
 # under the License.
 
 import functools
-from typing import Generator
+import typing as ty
-from typing import Generic
-from typing import Optional
-from typing import Type
-from typing import TypeVar
 import urllib
 from urllib.parse import urlparse
 
@@ -24,7 +20,7 @@ try:
 
     JSONDecodeError = simplejson.scanner.JSONDecodeError
 except ImportError:
-    JSONDecodeError = ValueError
+    JSONDecodeError = ValueError  # type: ignore
 import iso8601
 import jmespath
 from keystoneauth1 import adapter
@@ -33,7 +29,8 @@ from openstack import _log
 from openstack import exceptions
 from openstack import resource
 
-T = TypeVar('T')
+
+ResourceType = ty.TypeVar('ResourceType', bound=resource.Resource)
 
 
 # The _check_resource decorator is used on Proxy methods to ensure that
@@ -74,7 +71,7 @@ def normalize_metric_name(name):
     return name
 
 
-class Proxy(adapter.Adapter, Generic[T]):
+class Proxy(adapter.Adapter):
     """Represents a service."""
 
     retriable_status_codes = None
@@ -84,7 +81,7 @@ class Proxy(adapter.Adapter, Generic[T]):
     ``<service-type>_status_code_retries``.
     """
 
-    _resource_registry = dict()
+    _resource_registry: ty.Dict[str, ty.Type[resource.Resource]] = {}
     """Registry of the supported resourses.
 
     Dictionary of resource names (key) types (value).
@@ -431,7 +428,9 @@ class Proxy(adapter.Adapter, Generic[T]):
             self, '_connection', getattr(self.session, '_sdk_connection', None)
         )
 
-    def _get_resource(self, resource_type: Type[T], value, **attrs) -> T:
+    def _get_resource(
+        self, resource_type: ty.Type[ResourceType], value, **attrs
+    ) -> ResourceType:
         """Get a resource object to work on
 
         :param resource_type: The type of resource to operate on. This should
@@ -478,8 +477,12 @@ class Proxy(adapter.Adapter, Generic[T]):
         return value
 
     def _find(
-        self, resource_type: Type[T], name_or_id, ignore_missing=True, **attrs
+        self,
-    ) -> Optional[T]:
+        resource_type: ty.Type[ResourceType],
+        name_or_id,
+        ignore_missing=True,
+        **attrs,
+    ) -> ty.Optional[ResourceType]:
         """Find a resource
 
         :param name_or_id: The name or ID of a resource to find.
@@ -500,8 +503,12 @@ class Proxy(adapter.Adapter, Generic[T]):
 
     @_check_resource(strict=False)
     def _delete(
-        self, resource_type: Type[T], value, ignore_missing=True, **attrs
+        self,
-    ):
+        resource_type: ty.Type[ResourceType],
+        value,
+        ignore_missing=True,
+        **attrs,
+    ) -> ty.Optional[ResourceType]:
         """Delete a resource
 
         :param resource_type: The type of resource to delete. This should
@@ -538,8 +545,12 @@ class Proxy(adapter.Adapter, Generic[T]):
 
     @_check_resource(strict=False)
     def _update(
-        self, resource_type: Type[T], value, base_path=None, **attrs
+        self,
-    ) -> T:
+        resource_type: ty.Type[ResourceType],
+        value,
+        base_path=None,
+        **attrs,
+    ) -> ResourceType:
         """Update a resource
 
         :param resource_type: The type of resource to update.
@@ -563,7 +574,12 @@ class Proxy(adapter.Adapter, Generic[T]):
         res = self._get_resource(resource_type, value, **attrs)
         return res.commit(self, base_path=base_path)
 
-    def _create(self, resource_type: Type[T], base_path=None, **attrs):
+    def _create(
+        self,
+        resource_type: ty.Type[ResourceType],
+        base_path=None,
+        **attrs,
+    ) -> ResourceType:
         """Create a resource from attributes
 
         :param resource_type: The type of resource to create.
@@ -588,8 +604,11 @@ class Proxy(adapter.Adapter, Generic[T]):
         return res.create(self, base_path=base_path)
 
     def _bulk_create(
-        self, resource_type: Type[T], data, base_path=None
+        self,
-    ) -> Generator[T, None, None]:
+        resource_type: ty.Type[ResourceType],
+        data,
+        base_path=None,
+    ) -> ty.Generator[ResourceType, None, None]:
         """Create a resource from attributes
 
         :param resource_type: The type of resource to create.
@@ -612,13 +631,13 @@ class Proxy(adapter.Adapter, Generic[T]):
     @_check_resource(strict=False)
     def _get(
         self,
-        resource_type: Type[T],
+        resource_type: ty.Type[ResourceType],
         value=None,
         requires_id=True,
         base_path=None,
         skip_cache=False,
         **attrs,
-    ):
+    ) -> ResourceType:
         """Fetch a resource
 
         :param resource_type: The type of resource to get.
@@ -655,12 +674,12 @@ class Proxy(adapter.Adapter, Generic[T]):
 
     def _list(
         self,
-        resource_type: Type[T],
+        resource_type: ty.Type[ResourceType],
         paginated=True,
         base_path=None,
         jmespath_filters=None,
         **attrs,
-    ) -> Generator[T, None, None]:
+    ) -> ty.Generator[ResourceType, None, None]:
         """List a resource
 
         :param resource_type: The type of resource to list. This should
@@ -696,8 +715,12 @@ class Proxy(adapter.Adapter, Generic[T]):
         return data
 
     def _head(
-        self, resource_type: Type[T], value=None, base_path=None, **attrs
+        self,
-    ):
+        resource_type: ty.Type[ResourceType],
+        value=None,
+        base_path=None,
+        **attrs,
+    ) -> ResourceType:
         """Retrieve a resource's header
 
         :param resource_type: The type of resource to retrieve.

openstack/resource.py

@@ -32,10 +32,12 @@ converted into this Resource class' appropriate components and types
 and then returned to the caller.
 """
 
+import abc
 import collections
 import inspect
 import itertools
 import operator
+import typing as ty
 import urllib.parse
 import warnings
 
@@ -93,11 +95,11 @@ def _convert_type(value, data_type, list_type=None):
             return data_type()
 
 
-class _BaseComponent:
+class _BaseComponent(abc.ABC):
     # The name this component is being tracked as in the Resource
-    key = None
+    key: str
     # The class to be used for mappings
-    _map_cls = dict
+    _map_cls: ty.Type[ty.Mapping] = dict
 
     #: Marks the property as deprecated.
     deprecated = False
@@ -270,6 +272,8 @@ class Computed(_BaseComponent):
 class _ComponentManager(collections.abc.MutableMapping):
     """Storage of a component type"""
 
+    attributes: ty.Dict[str, ty.Any]
+
     def __init__(self, attributes=None, synchronized=False):
         self.attributes = dict() if attributes is None else attributes.copy()
         self._dirty = set() if synchronized else set(self.attributes.keys())
@@ -452,14 +456,15 @@ class Resource(dict):
     # will work properly.
 
     #: Singular form of key for resource.
-    resource_key = None
+    resource_key: ty.Optional[str] = None
     #: Plural form of key for resource.
-    resources_key = None
+    resources_key: ty.Optional[str] = None
     #: Key used for pagination links
     pagination_key = None
 
     #: The ID of this resource.
     id = Body("id")
+
     #: The name of this resource.
     name = Body("name")
     #: The OpenStack location of this resource.
@@ -469,7 +474,7 @@ class Resource(dict):
     _query_mapping = QueryParameters()
 
     #: The base part of the URI for this resource.
-    base_path = ""
+    base_path: str = ""
 
     #: Allow create operation for this resource.
     allow_create = False
@@ -508,22 +513,22 @@ class Resource(dict):
     create_returns_body = None
 
     #: Maximum microversion to use for getting/creating/updating the Resource
-    _max_microversion = None
+    _max_microversion: ty.Optional[str] = None
     #: API microversion (string or None) this Resource was loaded with
     microversion = None
 
     _connection = None
-    _body = None
+    _body: _ComponentManager
-    _header = None
+    _header: _ComponentManager
-    _uri = None
+    _uri: _ComponentManager
-    _computed = None
+    _computed: _ComponentManager
-    _original_body = None
+    _original_body: ty.Dict[str, ty.Any] = {}
     _store_unknown_attrs_as_properties = False
     _allow_unknown_attrs_in_body = False
-    _unknown_attrs_in_body = None
+    _unknown_attrs_in_body: ty.Dict[str, ty.Any] = {}
 
     # Placeholder for aliases as dict of {__alias__:__original}
-    _attr_aliases = {}
+    _attr_aliases: ty.Dict[str, str] = {}
 
     def __init__(self, _synchronized=False, connection=None, **attrs):
         """The base resource
@@ -1072,12 +1077,13 @@ class Resource(dict):
         :return: A dictionary of key/value pairs where keys are named
             as they exist as attributes of this class.
         """
+        mapping: ty.Union[utils.Munch, ty.Dict]
         if _to_munch:
             mapping = utils.Munch()
         else:
             mapping = {}
 
-        components = []
+        components: ty.List[ty.Type[_BaseComponent]] = []
         if body:
             components.append(Body)
         if headers:
@@ -1089,9 +1095,6 @@ class Resource(dict):
                 "At least one of `body`, `headers` or `computed` must be True"
             )
 
-        # isinstance stricly requires this to be a tuple
-        components = tuple(components)
-
         if body and self._allow_unknown_attrs_in_body:
             for key in self._unknown_attrs_in_body:
                 converted = self._attr_to_dict(
@@ -1105,7 +1108,8 @@ class Resource(dict):
         # but is slightly different in that we're looking at an instance
         # and we're mapping names on this class to their actual stored
         # values.
-        for attr, component in self._attributes_iterator(components):
+        # NOTE: isinstance stricly requires components to be a tuple
+        for attr, component in self._attributes_iterator(tuple(components)):
             if original_names:
                 key = component.name
             else:
@@ -1167,6 +1171,7 @@ class Resource(dict):
         *,
         resource_request_key=None,
     ):
+        body: ty.Union[ty.Dict[str, ty.Any], ty.List[ty.Any]]
         if patch:
             if not self._store_unknown_attrs_as_properties:
                 # Default case
@@ -1592,7 +1597,7 @@ class Resource(dict):
                 "Invalid create method: %s" % cls.create_method
             )
 
-        body = []
+        _body: ty.List[ty.Any] = []
         resources = []
         for attrs in data:
             # NOTE(gryf): we need to create resource objects, since
@@ -1605,9 +1610,12 @@ class Resource(dict):
             request = resource._prepare_request(
                 requires_id=requires_id, base_path=base_path
             )
-            body.append(request.body)
+            _body.append(request.body)
+
+        body: ty.Union[ty.Dict[str, ty.Any], ty.List[ty.Any]] = _body
 
         if prepend_key:
+            assert cls.resources_key
             body = {cls.resources_key: body}
 
         response = method(

openstack/service_description.py

@@ -11,6 +11,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import typing as ty
 import warnings
 
 import os_service_types
@@ -44,11 +45,11 @@ class _ServiceDisabledProxyShim:
 
 class ServiceDescription:
     #: Dictionary of supported versions and proxy classes for that version
-    supported_versions = None
+    supported_versions: ty.Dict[str, ty.Type[proxy_mod.Proxy]] = {}
     #: main service_type to use to find this service in the catalog
-    service_type = None
+    service_type: str
     #: list of aliases this service might be registered as
-    aliases = []
+    aliases: ty.List[str] = []
 
     def __init__(self, service_type, supported_versions=None, aliases=None):
         """Class describing how to interact with a REST service.

openstack/test/fakes.py

@@ -67,7 +67,7 @@ def generate_fake_resource(
     :raises NotImplementedError: If a resource attribute specifies a ``type``
         or ``list_type`` that cannot be automatically generated
     """
-    base_attrs = dict()
+    base_attrs: Dict[str, Any] = {}
     for name, value in inspect.getmembers(
         resource_type,
         predicate=lambda x: isinstance(x, (resource.Body, resource.URI)),
@@ -182,7 +182,7 @@ def generate_fake_resources(
 # (better) type annotations
 def generate_fake_proxy(
     service: Type[service_description.ServiceDescription],
-    api_version: Optional[int] = None,
+    api_version: Optional[str] = None,
 ) -> proxy.Proxy:
     """Generate a fake proxy for the given service type
 
@@ -246,10 +246,10 @@ def generate_fake_proxy(
             )
         else:
             api_version = list(supported_versions)[0]
-    elif str(api_version) not in supported_versions:
+    elif api_version not in supported_versions:
         raise ValueError(
             f"API version {api_version} is not supported by openstacksdk. "
             f"Supported API versions are: {', '.join(supported_versions)}"
         )
 
-    return mock.create_autospec(supported_versions[str(api_version)])
+    return mock.create_autospec(supported_versions[api_version])

openstack/tests/base.py

@@ -13,11 +13,12 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-from io import StringIO
+import io
 import logging
 import os
 import pprint
 import sys
+import typing as ty
 
 import fixtures
 from oslotest import base
@@ -59,8 +60,10 @@ class TestCase(base.BaseTestCase):
 
         self.warnings = self.useFixture(os_fixtures.WarningsFixture())
 
+        self._log_stream: ty.TextIO
+
         if os.environ.get('OS_LOG_CAPTURE') in _TRUE_VALUES:
-            self._log_stream = StringIO()
+            self._log_stream = io.StringIO()
             if os.environ.get('OS_ALWAYS_LOG') in _TRUE_VALUES:
                 self.addCleanup(self.printLogs)
             else:

openstack/utils.py

@@ -16,6 +16,7 @@ import queue
 import string
 import threading
 import time
+import typing as ty
 
 import keystoneauth1
 from keystoneauth1 import adapter as ks_adapter
@@ -417,7 +418,7 @@ class TinyDAG:
     def _start_traverse(self):
         """Initialize graph traversing"""
         self._run_in_degree = self._get_in_degree()
-        self._queue = queue.Queue()
+        self._queue: queue.Queue[str] = queue.Queue()
         self._done = set()
         self._it_cnt = len(self._graph)
 
@@ -427,8 +428,7 @@ class TinyDAG:
 
     def _get_in_degree(self):
         """Calculate the in_degree (count incoming) for nodes"""
-        _in_degree = dict()
+        _in_degree: ty.Dict[str, int] = {u: 0 for u in self._graph.keys()}
-        _in_degree = {u: 0 for u in self._graph.keys()}
         for u in self._graph:
             for v in self._graph[u]:
                 _in_degree[v] += 1
@@ -568,7 +568,7 @@ class Munch(dict):
 def munchify(x, factory=Munch):
     """Recursively transforms a dictionary into a Munch via copy."""
     # Munchify x, using `seen` to track object cycles
-    seen = dict()
+    seen: ty.Dict[int, ty.Any] = dict()
 
     def munchify_cycles(obj):
         try:
@@ -608,7 +608,7 @@ def unmunchify(x):
     """Recursively converts a Munch into a dictionary."""
 
     # Munchify x, using `seen` to track object cycles
-    seen = dict()
+    seen: ty.Dict[int, ty.Any] = dict()
 
     def unmunchify_cycles(obj):
         try: