docs: public static ClassFileVersion ofJavaVersionString(String javaVersionString) {
          if (javaVersionString.equals("1.1")) {
              return JAVA_V1;
          } else if (javaVersionString.equals("1.2")) {
              return JAVA_V2;
          } else if (javaVersionString.equals("1.3")) {
              return JAVA_V3;
          } else if (javaVersionString.equals("1.4")) {
              return JAVA_V4;
          } else if (javaVersionString.equals("1.5") || javaVersionString.equals("5")) {
              return JAVA_V5;
          } else if (javaVersionString.equals("1.6") || javaVersionString.equals("6")) {
              return JAVA_V6;
          } else if (javaVersionString.equals("1.7") || javaVersionString.equals("7")) {
              return JAVA_V7;
          } else if (javaVersionString.equals("1.8") || javaVersionString.equals("8")) {
              return JAVA_V8;
          } else if (javaVersionString.equals("1.9") || javaVersionString.equals("9")) {
              return JAVA_V9;
          } else if (javaVersionString.equals("1.10") || javaVersionString.equals("10")) {
              return JAVA_V10;
          } else if (javaVersionString.equals("1.11") || javaVersionString.equals("11")) {
              return JAVA_V11;
          } else if (javaVersionString.equals("1.12") || javaVersionString.equals("12")) {
              return JAVA_V12;
          } else if (javaVersionString.equals("1.13") || javaVersionString.equals("13")) {
              return JAVA_V13;
          } else {
              if (OpenedClassReader.EXPERIMENTAL) {
                  try {
                      int version = Integer.parseInt(javaVersionString.startsWith("1.")
                              ? javaVersionString.substring(2)
                              : javaVersionString);
                      if (version > 0) {
                          return new ClassFileVersion(BASE_VERSION + version);
                      }
                  } catch (NumberFormatException ignored) {
                  }
              }
              throw new IllegalArgumentException("Unknown Java version string: " + javaVersionString);
          }
      }