def dfs(self, s, t, visited):
        if s == t:
            return True

        visited.add(s)
        for nbr in s.neighbors:
            if nbr not in visited:
                if self.dfs(nbr, t, visited):
                    return True

        return False
Constructs a range filter using start and end properties.
dataset/ETHPy150Open algorhythms/LintCode/Route Between Two Nodes in Graph.py/Solution.dfs--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/datastore/datastore_query.py/_PropertyRangeFilter.__init__