static void validate(String name) {
    if (isRegisteredName(name)) {
      throw new IllegalArgumentException(
          String.format(
              "claim '%s' is invalid because it's a registered name; use the corresponding"
                  + " setter method.",
              name));
    }
  }
Supported protected headers, as described in https://tools.ietf.org/html/rfc7515#section-4.1
java_src/src/main/java/com/google/crypto/tink/jwt/JwtNames.java