Return an array mask.

        :param value: The array.
        :return: The array mask.

def fn_get_mask(self, value):
        """
        Return an array mask.

        :param value: The array.
        :return: The array mask.
        """

        value = self._to_ndarray(value)

        if numpy.ma.is_masked(value):
            return value.mask
        else:
            return numpy.zeros(value.shape).astype(bool)