docs: public SignUpRequest signUp(String email, String password, String connection) {
          Asserts.assertNotNull(email, "email");
          Asserts.assertNotNull(password, "password");
          Asserts.assertNotNull(connection, "connection");
  
          String url = baseUrl
                  .newBuilder()
                  .addPathSegment(PATH_DBCONNECTIONS)
                  .addPathSegment("signup")
                  .build()
                  .toString();
          CreateUserRequest request = new CreateUserRequest(client, url);
          request.addParameter(KEY_CLIENT_ID, clientId);
          request.addParameter(KEY_EMAIL, email);
          request.addParameter(KEY_PASSWORD, password);
          request.addParameter(KEY_CONNECTION, connection);
          return request;
      }