// custom_python at the model level should override only one model

message XOSModel (XOSBase) {
     option custom_python = True;
     required string name = 1 [max_length = 200, content_type = "stripped", blank = False, help_text = "Help Name", null = False, db_index = False];
     required string files = 2 [max_length = 1024, content_type = "stripped", blank = False, help_text = "Help Files", null = False, db_index = False];
}

message XOSModel2 (XOSBase) {
     required string name = 1 [max_length = 200, content_type = "stripped", blank = False, help_text = "Help Name", null = False, db_index = False];
     required string files = 2 [max_length = 1024, content_type = "stripped", blank = False, help_text = "Help Files", null = False, db_index = False];
}