docs: 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)