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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 _force_edge_active_move(self, state: _STATE) -> _STATE: """Move which forces a random edge to appear on some sequence. This move chooses random edge from the edges which do not belong to any sequence and modifies state in such a way, that this chosen edge appears on some sequence of the search state. Args: state: Search state, not mutated. Returns: New search state with one of the unused edges appearing in some sequence. """

        seqs, edges = state
        unused_edges = edges.copy()

        # List edges which do not belong to any linear sequence.
        for seq in seqs:
            for i in range(1, len(seq)):
                unused_edges.remove(self._normalize_edge((seq[i - 1], seq[i])))

        edge = self._choose_random_edge(unused_edges)
        if not edge:
            return seqs, edges

        return (
            self._force_edge_active(seqs,
                                    edge,
                                    lambda: bool(self._rand.randint(2))),
            edges)