code: @Path("{identifier}")
      public Object getExtensionResource(@PathParam("identifier") String identifier)
              throws GuacamoleException {
  
          // Retrieve authentication provider having given identifier
          AuthenticationProvider authProvider = getAuthenticationProvider(identifier);
          if (authProvider != null) {
  
              // Pull resource from authentication provider
              Object resource = authProvider.getResource();
              if (resource != null)
                  return resource;
  
          }
  
          // AuthenticationProvider-specific resource could not be found
          throw new GuacamoleResourceNotFoundException("No such resource.");
  
      }
docs: Returns the arbitrary REST resource exposed by the AuthenticationProvider
  having the given identifier.
  
  @param identifier
  The identifier of the AuthenticationProvider whose REST resource
  should be retrieved.
  
  @return
  The arbitrary REST resource exposed by the AuthenticationProvider
  having the given identifier.
  
  @throws GuacamoleException
  If no such resource could be found, or if an error occurs while
  retrieving that resource.