anchor.diff:    Do(Statement body, this.test) : super(body);
   
     accept(NodeVisitor visitor) => visitor.visitDo(this);
  +  void visitChildren(NodeVisitor visitor) {
  +    body.accept(visitor);
  +    test.accept(visitor);
  +  }
   }
   
   class Continue extends Statement {
  
positive.code:   Labeled(this.id, this.body);
  
    accept(NodeVisitor visitor) => visitor.visitLabeled(this);
  }
  
  abstract class Expression extends Node {
  
negative.code:   ArrayElement(this.index, this.value);
  
    accept(NodeVisitor visitor) => visitor.visitArrayElement(this);
    void visitChildren(NodeVisitor visitor) {
      value.accept(visitor);
    }
  }
  
  // Despite being called "Literal" the [ObjectLiteral] does not inherit from
  