Tests whether all elements evaluate True

        Returns
        -------
        all : bool

        See Also
        --------
        numpy.all

def all(self, axis=None, *args, **kwargs):
        """
        Tests whether all elements evaluate True

        Returns
        -------
        all : bool

        See Also
        --------
        numpy.all
        """
        nv.validate_all(args, kwargs)

        values = self.sp_values

        if len(values) != len(self) and not np.all(self.fill_value):
            return False

        return values.all()