code: def can_process(self, pairs):
          
          i, j = pairs
  
          # Neither points are in a route
          if i.route_allocation() is None or j.route_allocation() is None:
              return True
  
          if self._allocated == len(list(self._problem.nodes())) - 1: # All nodes in a route
              return False
  
          return False
docs: Returns True if this solution can process `pairs`
  
          Parameters
          ----------
          pairs: :any:`list` of pairs of Route
              List of pairs
              
          Returns
          -------
          bool
              True if this solution can process `pairs`.