code: public Observable<UserAccessList> listAsync(UUID appId) {
          return listWithServiceResponseAsync(appId).map(new Func1<ServiceResponse<UserAccessList>, UserAccessList>() {
              @Override
              public UserAccessList call(ServiceResponse<UserAccessList> response) {
                  return response.body();
              }
          });
      }
docs: Gets the list of user emails that have permissions to access your application.
  
  @param appId The application ID.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the UserAccessList object