code: public void visitOuterClass(String owner, String name, String desc) {
          if (cv != null) {
              cv.visitOuterClass(owner, name, desc);
          }
      }
docs: Visits the enclosing class of the class. This method must be called only
  if the class has an enclosing class.
  
  @param owner
  internal name of the enclosing class of the class.
  @param name
  the name of the method that contains the class, or
  <tt>null</tt> if the class is not enclosed in a method of its
  enclosing class.
  @param desc
  the descriptor of the method that contains the class, or
  <tt>null</tt> if the class is not enclosed in a method of its
  enclosing class.