//
   // Generated by JTB 1.3.2
   //
   
   package com.randomnoun.common.jexl.ast;
   
   /**
    * Represents an grammar optional node, e.g. ( A )? or [ A ]
    */
  public class NodeOptional implements Node {
     public NodeOptional() {
        node = null;
     }
  
     public NodeOptional(Node n) {
        addNode(n);
     }
  
     public void addNode(Node n)  {
        if ( node != null)                // Oh oh!
           throw new Error("Attempt to set optional node twice");
  
        node = n;
     }
     public void accept(com.randomnoun.common.jexl.visitor.Visitor v) {
        v.visit(this);
     }
     public <R,A> R accept(com.randomnoun.common.jexl.visitor.GJVisitor<R,A> v, A argu) {
        return v.visit(this,argu);
     }
     public <R> R accept(com.randomnoun.common.jexl.visitor.GJNoArguVisitor<R> v) {
        return v.visit(this);
     }
     public <A> void accept(com.randomnoun.common.jexl.visitor.GJVoidVisitor<A> v, A argu) {
        v.visit(this,argu);
     }
     public boolean present()   { return node != null; }
  
     public Node node;
  }