def __getattr__(cls, item):
    """
        Special warning for attribute errors.
        Its likely that user may have wanted to use a model interface
        instead of the Base class.
        """
    raise AttributeError(
        "'{0}' has no attribute '{1}'. Method may be a ModelInterface method. Did you mean '<yoursession>.{0}.{1}'?"
        .format(cls.__name__, item))
