code: public Service retrieve(final RequestContext requestContext, final WebContext webContext, final BaseClient client) {
          val clientId = getDelegatedClientId(webContext, client);
          val ticket = retrieveSessionTicketViaClientId(webContext, clientId);
          restoreDelegatedAuthenticationRequest(requestContext, webContext, ticket);
          LOGGER.debug("Removing delegated client identifier [{}} from registry", ticket.getId());
          this.ticketRegistry.deleteTicket(ticket.getId());
          return ticket.getService();
  
      }
docs: Retrieve service.
  
  @param requestContext the request context
  @param webContext     the web context
  @param client         the client
  @return the service