Method unlock

chapter21/src/main/java/com/seaofnodes/simple/node/Node.java:595–600

()

    }
    Node copyF() { return null; }

    // ------------------------------------------------------------------------
    // Peephole utilities

    // Swap inputs without letting either input go dead during the swap.
    public Node swap12() {
        unlock();               // Hash is order dependent
        _inputs.swap(1,2);
        return this;