code: @Override
      public void visitField(Field obj) {
          String fieldSig = obj.getSignature();
          if ("Ljavax/swing/JLabel;".equals(fieldSig)) {
              FieldAnnotation fa = FieldAnnotation.fromVisitedField(this);
  
              fieldLabels.add(XFactory.createXField(fa));
          }
      }
docs: looks for fields that are JLabels and stores them in a set
  
  @param obj
  the field object of the current field