code: def remove_zero_normals(self):
          
          points_of_interest = np.where(np.linalg.norm(self._data, axis=0) != 0.0)[0]
          self._data = self._data[:, points_of_interest]
docs: Removes normal vectors with a zero magnitude.
  
          Note
          ----
          This returns nothing and updates the NormalCloud in-place.