code: def error_response(self, kwargs_lens, kwargs_ps):
          
          C_D_response, model_error = [], []
          for i in range(self._num_bands):
              if self._compute_bool[i] is True:
                  kwargs_lens_i = [kwargs_lens[k] for k in self._idex_lens_list[i]]
                  C_D_response_i, model_error_i = self._imageModel_list[i].error_response(kwargs_lens_i, kwargs_ps)
                  model_error.append(model_error_i)
                  if C_D_response == []:
                      C_D_response = C_D_response_i
                  else:
                      C_D_response = np.append(C_D_response, C_D_response_i)
          return C_D_response, model_error
docs: returns the 1d array of the error estimate corresponding to the data response
  
          :return: 1d numpy array of response, 2d array of additonal errors (e.g. point source uncertainties)