feat: implement admin metadata typings (#30)

confluent_kafka-stubs/admin/_metadata.pyi

@@ -2,3 +2,60 @@
 types-confluent-kafka: A package providing type hints for the confluent-kafka Python package.
 This package is licensed under the Apache 2.0 License.
 """
+
+from __future__ import annotations
+
+# standard library
+from typing import TYPE_CHECKING, Any, ClassVar
+
+if TYPE_CHECKING:
+    # pypi/conda library
+    from confluent_kafka._model import ConsumerGroupState
+    from confluent_kafka.cimpl import KafkaError
+
+class ClusterMetadata:
+    cluster_id: ClassVar[str]
+    controller_id: ClassVar[int] = -1
+    brokers: ClassVar[dict[int, "BrokerMetadata"] | None] = None
+    topics: ClassVar[dict[int, "TopicMetadata"] | None] = None
+    orig_broker_id: ClassVar[int] = -1
+    orig_broker_name: ClassVar[str] = ""
+    def __init__(self) -> None: ...
+
+class BrokerMetadata:
+    id: ClassVar[int] = -1
+    host: ClassVar[str] | None = None
+    port: ClassVar[int] = -1
+    def __init__(self) -> None: ...
+
+class TopicMetadata:
+    topic: ClassVar[str | None] = None
+    partitions: ClassVar[dict[int, "PartitionMetadata"] | None] = None
+    error: ClassVar["KafkaError" | None] = None
+    def __init__(self) -> None: ...
+
+class PartitionMetadata:
+    id: ClassVar[int]
+    leader: ClassVar[int]
+    replicas: ClassVar[list[int] | None] = None
+    isrs: ClassVar[list[int] | None] = None
+    error: ClassVar["KafkaError" | None] = None
+    def __init__(self) -> None: ...
+
+class GroupMember:
+    id: ClassVar[int | None] = None
+    client_id: ClassVar[str | None] = None
+    client_host: ClassVar[str | None] = None
+    metadata: ClassVar[Any | None] = None
+    assignment: ClassVar[Any | None] = None
+    def __init__(self) -> None: ...
+
+class GroupMetadata:
+    broker: ClassVar["BrokerMetadata" | None] = None
+    id: ClassVar[str | None] = None
+    error: ClassVar["KafkaError" | None] = None
+    state: ClassVar["ConsumerGroupState" | None] = None
+    protocol_type: ClassVar[Any | None] = None
+    protocol: ClassVar[Any] = None
+    members: ClassVar[list | None] = None
+    def __init__(self) -> None: ...