Set,
    Type,
    Union,
    cast,
)
from weakref import WeakKeyDictionary

import fastapi
from fastapi._compat import (
    PYDANTIC_V2,
    BaseConfig,
    ModelField,
    PydanticSchemaGenerationError,
    Undefined,
    UndefinedType,
    Validator,
    lenient_issubclass,
)
from fastapi.datastructures import DefaultPlaceholder, DefaultType
from pydantic import BaseModel, create_model

    frozenset: frozenset,
    Deque: deque,
    deque: deque,
}

sequence_types = tuple(sequence_annotation_to_type.keys())

if PYDANTIC_V2:
    from pydantic import PydanticSchemaGenerationError as PydanticSchemaGenerationError
    from pydantic import TypeAdapter
    from pydantic import ValidationError as ValidationError
    from pydantic._internal._schema_generation_shared import (  # type: ignore[attr-defined]