docs: def _check_cutoff(self):
          """
          Returns a function to stop the search of the investigated node of the
          ArciDispatch algorithm.
  
          :return:
              A function to stop the search.
          :rtype: (int | float) -> bool
          """
  
          if self.cutoff is not None:
  
              cutoff = self.cutoff  # Namespace shortcut for speed.
  
              def check_cutoff(distance):
                  """
                  Stops the search of the investigated node of the ArciDispatch
                  algorithm.
  
                  :param distance:
                      Distance from the starting node.
                  :type distance: float, int
  
                  :return:
                      True if distance > cutoff, otherwise False.
                  :rtype: bool
                  """
  
                  return distance > cutoff  # Check cutoff distance.
  
          else:  # cutoff is None.
              # noinspection PyUnusedLocal
              def check_cutoff(distance):
                  return False
  
          return check_cutoff