def _validate_model_name(model_obj, model_name: str) ->bool:
    """
    Validates the inputted model name. If the object already has an
    attribute with that model name, it is invalid
    
    Parameters
    ----------
    model_name : str
        Proposed name of the model
        
    model_obj : Model
        Model object
    
    Returns
    -------
    bool
        True if model name is valid, false otherwise
    """
    if hasattr(model_obj, model_name) and model_name not in model_obj._models:
        return False
    return True
