def METHOD_NAME(self, field: "BaseField") -> None:
    """
    Registers relation in the manager.
    Adds Relation instance under field.name.
    :param field: field with relation declaration
    :type field: BaseField
    """
    self._relations[field.name] = Relation(
        manager=self,
        type_=self._get_relation_type(field),
        field_name=field.name,
        to=field.to,
        through=getattr(field, "through", None),
    )