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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _set_flow_entry(self, datapath, actions, in_port, dst, src=None):
 """set a flow entry."""

        set_flow = self._set_flow_func.get(datapath.ofproto.OFP_VERSION)
        assert set_flow
        set_flow(datapath, actions, in_port, dst, src)