docs: public DescribeScalingPlansRequest withApplicationSources(ApplicationSource... applicationSources) {
          if (this.applicationSources == null) {
              setApplicationSources(new java.util.ArrayList<ApplicationSource>(applicationSources.length));
          }
          for (ApplicationSource ele : applicationSources) {
              this.applicationSources.add(ele);
          }
          return this;
      }