def extract_related_fields(cls) -> List["ForeignKeyField"]:
        """
        Returns List of ormar Fields for all relations declared on a model.
        List is cached in cls._related_fields for quicker access.

        :return: list of related fields
        :rtype: List
        """
        if cls._related_fields is not None:
            return cls._related_fields

        related_fields = []
        for name in cls.extract_related_names().union(cls.extract_through_names()):
            related_fields.append(
                cast("ForeignKeyField", cls.ormar_config.model_fields[name])
            )
        cls._related_fields = related_fields

        return related_fields

        Returns List of ormar Fields for all relations declared on a model.
        List is cached in cls._related_fields for quicker access.

        :return: list of related fields
        :rtype: List
        
ormar/models/mixins/relation_mixin.py