code: def run_searchlight(self, voxel_fn, pool_size=None):
          
  
          extra_block_fn_params = (voxel_fn, self.shape,
                                   self.min_active_voxels_proportion)
          block_fn_result = self.run_block_function(_singlenode_searchlight,
                                                    extra_block_fn_params,
                                                    pool_size)
          return block_fn_result
docs: Perform a function at each voxel which is set to True in the
          user-provided mask. The mask passed to the searchlight function will be
          further masked by the user-provided searchlight shape.
  
          Parameters
          ----------
  
          voxel_fn: function to apply at each voxel
  
              Must be `serializeable using pickle
              <https://docs.python.org/3/library/pickle.html#what-can-be-pickled-and-unpickled>`_.
  
                  Parameters
  
                  subj: list of 4D arrays containing subset of subject data
  
                  mask: 3D array containing subset of mask data
  
                  sl_rad: radius, in voxels, of the sphere inscribed in the
                  cube
  
                  bcast_var: shared data which is broadcast to all processes
  
  
                  Returns
  
                  Value of any pickle-able type
  
          Returns
          -------
  
          A volume which is the same size as the mask, however a number of voxels
          equal to the searchlight radius has been removed from each border of
          the volume. This volume contains the values returned from the
          searchlight function at each voxel which was set to True in the mask,
          and None elsewhere.