Given the name of a dynamic field, and a dynamic part, return the
        name of the final dynamic field to use. It will then be used with
        get_field.

def get_field_name_for(cls, field_name, dynamic_part):
        """
        Given the name of a dynamic field, and a dynamic part, return the
        name of the final dynamic field to use. It will then be used with
        get_field.
        """
        field = cls.get_field(field_name)
        return field.get_name_for(dynamic_part)