docs: public static int getVersionId(String version) throws IllegalStateException {
          int versionID = 0;
          if ("4.0".equals(version)) {
              versionID = 40;
          }else if ("3.1".equals(version)) {
              versionID = 31;
          } else if ("3.0".equals(version)) {
              versionID = 30;
          } else if ("2.5".equals(version)) {
              versionID = 25;
          } else if ("2.4".equals(version)) {
              versionID = 24;
          } else if ("2.3".equals(version)) {
              versionID = 23;
          } else if ("2.2".equals(version)) {
              versionID = 22;
          } else {
              throw new IllegalStateException("invalid web-app version");
          }
          return versionID;
      }