public function testHasConfig()
 {
     $client = new Client();
     $description = new Description([]);
     $guzzle = new GuzzleClient($client, $description, ['foo' => 'bar', 'baz' => ['bam' => 'boo']]);
     $this->assertSame($client, $guzzle->getHttpClient());
     $this->assertSame($description, $guzzle->getDescription());
     $this->assertEquals('bar', $guzzle->getConfig('foo'));
     $this->assertEquals('boo', $guzzle->getConfig('baz/bam'));
     $this->assertEquals([], $guzzle->getConfig('defaults'));
     $guzzle->setConfig('abc/123', 'listen');
     $this->assertEquals('listen', $guzzle->getConfig('abc/123'));
     $this->assertCount(1, $guzzle->getEmitter()->listeners('process'));
 }