code: public static EmptyTypeDeclaration mergeType(EmptyTypeDeclaration one, EmptyTypeDeclaration two) {
          if (isAllNull(one, two)) return null;
  
          EmptyTypeDeclaration etd = null;
  
          if (isAllNotNull(one, two)) {
  
              etd = new EmptyTypeDeclaration();
              etd.setName(one.getName());
              etd.setJavaDoc(mergeSelective(one.getJavaDoc(), two.getJavaDoc()));
              etd.setComment(mergeSelective(one.getComment(), two.getComment()));
              etd.setAnnotations(mergeListNoDuplicate(one.getAnnotations(), two.getAnnotations()));
              etd.setMembers(mergeBodies(one.getMembers(), two.getMembers()));
              etd.setModifiers(mergeModifiers(one.getModifiers(), two.getModifiers()));
  
              LOG.info("merge EmptyTypeDeclaration --> {}", etd.getName());
          } else {
              etd = findFirstNotNull(one, two);
              LOG.info("add EmptyTypeDeclaration --> {}", etd.getName());
          }
          return etd;
      }
docs: /*
  合并空类型声明