code: @SuppressWarnings("WeakerAccess")
      public Request<UserProfile, ManagementException> getProfile(String userId) {
          HttpUrl url = HttpUrl.parse(auth0.getDomainUrl()).newBuilder()
                  .addPathSegment(API_PATH)
                  .addPathSegment(V2_PATH)
                  .addPathSegment(USERS_PATH)
                  .addPathSegment(userId)
                  .build();
  
          return factory.GET(url, client, gson, UserProfile.class, mgmtErrorBuilder);
      }
docs: Get the User Profile calling <a href="https://auth0.com/docs/api/management/v2#!/Users/get_users_by_id">'/api/v2/users/:userId'</a> endpoint
  Example usage:
  <pre>
  {@code
  client.getProfile("{user id}")
  .start(new BaseCallback<UserProfile, ManagementException>() {
  {@literal}Override
  public void onSuccess(UserProfile payload) {}
  
  {@literal}Override
  public void onFailure(ManagementException error) {}
  });
  }
  </pre>
  
  @param userId identity of the user
  @return a request to start