code: public ClassNode visitTree($.Visitor<ClassNode> visitor, final boolean publicOnly, final boolean noAbstract) {
          return visitTree($.guardedVisitor(classNodeFilter(publicOnly, noAbstract), visitor));
      }
docs: Accept a visitor that visit all descendants of the class represetned by
  this `ClassNode` including this `ClassNode` itself.
  @param visitor the visitor
  @param publicOnly specify if only public class shall be visited
  @param noAbstract specify if abstract class can be visited
  @return this `ClassNode` instance