code: public function instantiate($provider)
      {
          if (!$this->supported($provider)) {
              throw new ProviderNotSupportedException($provider);
          }
  
          $class = $this->providerClass($provider);
  
          switch ($provider) {
              case 'facebook':
                  return new $class($this->config,
                          $this->redirector,
                          $this->http,
                          $this->store,
                          $this->profile,
                          $this->access_token);
              break;
  
              case 'twitter':
                  return new $class($this->config,
                                  $this->http,
                                  $this->redirector,
                                  $this->store,
                                  $this->profile,
                                  $this->signature,
                                  $this->consumer,
                                  $this->token,
                                  $this->oauth);
              break;
          }
      }
docs: Instantiates and returns a
  social provider instance.
  
  @param string $provider
  
  @return Vinelab\Auth\Contracts\ProviderInterface