code: public List<User> getAllUsers(AccessToken accessToken, String... attributes) {
          return getUserService().getAllUsers(accessToken, attributes);
      }
docs: Retrieve a list of the of all {@link User} resources saved in the OSIAM service. If you need to have all User but
  the number is very large, this method can be slow. In this case you can also use Query.Builder with no filter to
  split the number of User returned
  
  @param accessToken A valid AccessToken
  @param attributes  the list of attributes that should be returned in the response
  @return a list of all Users
  @throws UnauthorizedException             if the request could not be authorized.
  @throws ForbiddenException                if the scope doesn't allow this request
  @throws ConnectionInitializationException if the connection to the given OSIAM service could not be initialized
  @throws IllegalStateException             if OSIAM's endpoint(s) are not properly configured