) -> CoreSchema:
            return with_info_plain_validator_function(cls._validate)


class BaseModelWithConfig(BaseModel):
    if PYDANTIC_V2:
        model_config = {"extra": "allow"}

    else:

        class Config:
            extra = "allow"


class Contact(BaseModelWithConfig):
    name: Optional[str] = None
    url: Optional[AnyUrl] = None

    ) -> Any:
        return model.model_dump(mode=mode, **kwargs)

    def _get_model_config(model: BaseModel) -> Any:
        return model.model_config

    def get_schema_from_model_field(
        *,
        field: ModelField,
        schema_generator: GenerateJsonSchema,
        model_name_map: ModelNameMap,
        field_mapping: Dict[

    * You can read more about it in the docs for [Declare Request Example Data](https://fastapi.tiangolo.com/tutorial/schema-extra-example/).
* The attribute `schema_extra` for the internal class `Config` has been replaced by the key `json_schema_extra` in the new `model_config` dict.