def __call__(self, start, end):
        """
        Estimate how far start is from end.
        
        @type  start: node
        @param start: Start node.
        
        @type  end: node
        @param end: End node.
        """
        assert len(list(self.distances.keys())) > 0, "You need to optimize this heuristic for your graph before it can be used to estimate."
                
        return self.distances[(start,end)]
dataset/ETHPy150Open nerdvegas/rez/src/rez/vendor/pygraph/algorithms/heuristics/euclidean.py/euclidean.__call__/original