* Specifies that all tree walker rules call {@code traceIn}/{@code traceOut}.
     */
    @Input
    public boolean isTraceTreeWalker() {
        return traceTreeWalker;
    }

    public void setTraceTreeWalker(boolean traceTreeWalker) {
        this.traceTreeWalker = traceTreeWalker;
    }

    /**
     * The maximum heap size for the forked antlr process (ex: '1g').
     */
    @Internal