Amp\Test\Artax\MessageTest::testAppendHeaderAddsToExistingHeaderIfAlreadyExists PHP Method

    public function testAppendHeaderAddsToExistingHeaderIfAlreadyExists()
    {
        $msg = $this->getMockForAbstractClass('Amp\\Artax\\Message');
        $msg->appendHeader('My-Header', 'val1');
        $this->assertEquals(['val1'], $msg->getHeader('my-header'));
        $msg->appendHeader('my-heAder', ['val2']);
        $msg->appendHeader('MY-HEADER', 'val3');
        $this->assertEquals(['val1', 'val2', 'val3'], $msg->getHeader('my-header'));
    }