@Override
  public String toString() {
    JsonObject header = new JsonObject();
    if (typeHeader.isPresent()) {
      header.add("typ", new JsonPrimitive(typeHeader.get()));
    }
    return header + "." + payload;
  }
Returns a brief description of a RawJwt object. The exact details of the representation are
unspecified and subject to change.
java_src/src/main/java/com/google/crypto/tink/jwt/RawJwt.java