code: def lens_center(self, kwargs_lens, k=None, bool_list=None, numPix=200, deltaPix=0.01, center_x_init=0, center_y_init=0):
          
          x_grid, y_grid = util.make_grid(numPix=numPix, deltapix=deltaPix)
          x_grid += center_x_init
          y_grid += center_y_init
  
          if bool_list is None:
              kappa = self._lensModel.kappa(x_grid, y_grid, kwargs_lens, k=k)
          else:
              kappa = np.zeros_like(x_grid)
              for k in range(len(kwargs_lens)):
                  if bool_list[k] is True:
                      kappa += self._lensModel.kappa(x_grid, y_grid, kwargs_lens, k=k)
          center_x = x_grid[kappa == np.max(kappa)]
          center_y = y_grid[kappa == np.max(kappa)]
          return center_x, center_y
docs: computes the convergence weighted center of a lens model
  
          :param kwargs_lens: lens model keyword argument list
          :param bool_list: bool list (optional) to include certain models or not
          :return: center_x, center_y