code: public Client getClient(String clientId, AccessToken accessToken) {
          return getAuthService().getClient(clientId, accessToken);
      }
docs: Get client by the given client id.
  
  @param clientId    the client id
  @param accessToken the access token used to access the service
  @return The found client
  @throws UnauthorizedException             if the accessToken is not valid
  @throws ForbiddenException                if access to this resource is not allowed
  @throws ConnectionInitializationException if the connection to the given OSIAM service could not be initialized
  @throws ClientNotFoundException           if no client with the given id can be found
  @throws IllegalStateException             if OSIAM's endpoint(s) are not properly configured