public function testHeaders() { $headers = new Headers(); $this->assertTrue($headers instanceof \IteratorAggregate); $this->assertTrue($headers instanceof \Traversable); $this->assertTrue($headers instanceof \ArrayAccess); $this->assertTrue($headers instanceof \Serializable); $this->assertTrue($headers instanceof \Countable); $client = new Client(); $client->setDefaultRequestHeaders($headers); $this->assertTrue($headers === $client->getDefaultRequestHeaderds()); // Default initialization $client = new Client(); $headers = $client->getDefaultRequestHeaderds(); $this->assertTrue($headers instanceof Headers); $this->assertTrue($headers === $client->getDefaultRequestHeaderds()); $this->assertArrayHasKey('User-Agent', $headers); $this->assertEquals('fb-php-ads-' . Api::VERSION, $headers['User-Agent']); }