def register_through_shortcut_fields(model_field: "ManyToManyField") -> None:
    """
    Registers m2m relation through shortcut on both ends of the relation.

    :param model_field: relation field defined in parent model
    :type model_field: ManyToManyField
    """
    through_model = model_field.through
    through_name = through_model.get_name(lower=True)
    related_name = model_field.get_related_name()

    model_field.owner.ormar_config.model_fields[through_name] = Through(
        through_model,
        real_name=through_name,
        virtual=True,
        related_name=model_field.name,
        owner=model_field.owner,
        nullable=True,
    )

    model_field.to.ormar_config.model_fields[through_name] = Through(
        through_model,
        real_name=through_name,
        virtual=True,
        related_name=related_name,
        owner=model_field.to,
        nullable=True,
    )
    setattr(model_field.owner, through_name, RelationDescriptor(name=through_name))
    setattr(model_field.to, through_name, RelationDescriptor(name=through_name))

    Registers m2m relation through shortcut on both ends of the relation.

    :param model_field: relation field defined in parent model
    :type model_field: ManyToManyField
    
ormar/models/helpers/relations.py