src/Google/AuthHandler/AuthHandlerFactory.php
public static function build($cache = null, array $cacheConfig = [])
  {
    $version = ClientInterface::VERSION;

    switch ($version[0]) {
      case '5':
        return new Google_AuthHandler_Guzzle5AuthHandler($cache, $cacheConfig);
      case '6':
        return new Google_AuthHandler_Guzzle6AuthHandler($cache, $cacheConfig);
      default:
        throw new Exception('Version not supported');
    }
  }
public static function build($cache = null, array $cacheConfig = [])
  {
    $version = ClientInterface::VERSION;

    switch ($version[0]) {
      case '5':
        return new Google_AuthHandler_Guzzle5AuthHandler($cache, $cacheConfig);
      case '6':
        return new Google_AuthHandler_Guzzle6AuthHandler($cache, $cacheConfig);
      default:
        throw new Exception('Version not supported');
    }
  }
Builds out a default http handler for the installed version of guzzle.

@return Google_AuthHandler_Guzzle5AuthHandler|Google_AuthHandler_Guzzle6AuthHandler
@throws Exception