public MetaInfoBuilder addComments(String... comments) {
   if (comments == null) {
     return this;
   }
   if (meta.getComments() == null) {
     meta.setComments(new ArrayList<>());
   }
   meta.getComments().addAll(Arrays.asList(comments));
   return this;
 }
 public MetaInfoBuilder addContributors(String... contributors) {
   if (contributors == null) {
     return this;
   }
   if (meta.getContributors() == null) {
     meta.setContributors(new HashSet<>());
   }
   meta.getContributors().addAll(Arrays.asList(contributors));
   return this;
 }
 public MetaInfoBuilder addTitles(String... titles) {
   if (titles == null) {
     return this;
   }
   if (meta.getTitles() == null) {
     meta.setTitles(new HashSet<>());
   }
   meta.getTitles().addAll(Arrays.asList(titles));
   return this;
 }
 public MetaInfoBuilder addAudiences(String... audiences) {
   if (audiences == null) {
     return this;
   }
   if (meta.getAudiences() == null) {
     meta.setAudiences(new HashSet<>());
   }
   meta.getAudiences().addAll(Arrays.asList(audiences));
   return this;
 }
 public MetaInfoBuilder addSeeAlso(String... seeAlso) {
   if (seeAlso == null) {
     return this;
   }
   if (meta.getSeeAlso() == null) {
     meta.setSeeAlso(new HashSet<>());
   }
   meta.getSeeAlso().addAll(Arrays.asList(seeAlso));
   return this;
 }
 public MetaInfoBuilder addSubjects(String... subjects) {
   if (subjects == null) {
     return this;
   }
   if (meta.getSubjects() == null) {
     meta.setSubjects(new HashSet<>());
   }
   meta.getSubjects().addAll(Arrays.asList(subjects));
   return this;
 }
 public MetaInfoBuilder addRights(String... rights) {
   if (rights == null) {
     return this;
   }
   if (meta.getRights() == null) {
     meta.setRights(new HashSet<>());
   }
   meta.getRights().addAll(Arrays.asList(rights));
   return this;
 }
 public MetaInfoBuilder addPublishers(String... publishers) {
   if (publishers == null) {
     return this;
   }
   if (meta.getPublishers() == null) {
     meta.setPublishers(new HashSet<>());
   }
   meta.getPublishers().addAll(Arrays.asList(publishers));
   return this;
 }
 public MetaInfoBuilder addIdentifiers(String... ids) {
   if (ids == null) {
     return this;
   }
   if (meta.getIdentifiers() == null) {
     meta.setIdentifiers(new HashSet<>());
   }
   meta.getIdentifiers().addAll(Arrays.asList(ids));
   return this;
 }
 public MetaInfoBuilder addSources(String... sources) {
   if (sources == null) {
     return this;
   }
   if (meta.getHasSources() == null) {
     meta.setHasSources(new HashSet<>());
   }
   meta.getHasSources().addAll(Arrays.asList(sources));
   return this;
 }
 public MetaInfoBuilder addDescriptions(String... descriptions) {
   if (descriptions == null) {
     return this;
   }
   if (meta.getDescriptions() == null) {
     meta.setDescriptions(new HashSet<>());
   }
   meta.getDescriptions().addAll(Arrays.asList(descriptions));
   return this;
 }
 public MetaInfoBuilder setCurrentDate() {
   meta.setDate(new Date());
   return this;
 }
 public MetaInfoBuilder setDate(Date date) {
   meta.setDate(date);
   return this;
 }