code: protected void doLoginByGivenEntity(USER_ENTITY givenEntity, LoginSpecifiedOption option) {
          assertGivenEntityRequired(givenEntity);
          handleLoginSuccess(givenEntity, option);
      }
docs: Do actually login for the user by given entity. (no silent)
  @param givenEntity The given entity for user. (NotNull)
  @param option The option of login specified by caller. (NotNull)