langchain/tools/openapi/utils/api_models.py/APIProperty/_get_schema_type_for_array
class APIProperty:    def _get_schema_type_for_array(
        schema: Schema,
    ) -> Optional[Union[str, Tuple[str, ...]]]:
        items = schema.items
        if isinstance(items, Schema):
            schema_type = APIProperty._cast_schema_list_type(items)
        elif isinstance(items, Reference):
            ref_name = items.ref.split("/")[-1]
            schema_type = ref_name  # TODO: Add ref definitions to make his valid
        else:
            raise ValueError(f"Unsupported array items: {items}")

        if isinstance(schema_type, str):
            # TODO: recurse
            schema_type = (schema_type,)

        return schema_type