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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 node_val_set(self, graph, node, key, branch, turn, tick, value):
 """Set a key-value pair on a node at a specific branch and revision"""

        if (branch, turn, tick) in self._btts:
            raise TimeError
        self._btts.add((branch, turn, tick))
        graph, node, key, value = map(self.pack, (graph, node, key, value))
        self._nodevals2set.append((graph, node, key, branch, turn, tick, value))