def METHOD_NAME(self, field):
    """
    Only computes min and max bounds of neighbouring cells
    """
    self._update_centroids(field)
    self.max_field.assign(-1.0e10)  # small number
    self.min_field.assign(1.0e10)  # big number
    par_loop(self._min_max_loop,
             dx,
             {"maxq": (self.max_field, MAX),
              "minq": (self.min_field, MIN),
              "q": (self.centroids, READ)})