assertHasAccessTokenOrKeys() public method

 /**
  *
  * @param Gateway $gateway
  */
 public function __construct($gateway)
 {
     $this->_gateway = $gateway;
     $this->_config = $gateway->config;
     $this->_config->assertHasAccessTokenOrKeys();
     $this->_http = new Http($gateway->config);
 }
 public function testValidWithOAuthClientCredentialsAndAccessToken()
 {
     $config = new Braintree\Configuration(['clientId' => 'client_id$development$integration_client_id', 'clientSecret' => 'client_secret$development$integration_client_secret', 'accessToken' => 'access_token$development$integration_merchant_id$integration_access_token']);
     $config->assertHasClientCredentials();
     $config->assertHasAccessTokenOrKeys();
 }