Method cfg0

chapter20/src/main/java/com/seaofnodes/simple/node/Node.java:147–147

()

    public boolean isUnused() { return nOuts() == 0; }

    public CFGNode cfg0() { return (CFGNode)in(0); }

    /**
     * Change a <em>def</em> into a Node.  Keeps the edges correct, by removing