public function testRemoveHeader()
{
$msg = $this->getMockForAbstractClass('Amp\\Artax\\Message');
$msg->appendHeader('My-Header', ['val1', 'val2']);
$this->assertTrue($msg->hasHeader('my-header'));
$msg->removeHeader('MY-HEADER');
$this->assertFalse($msg->hasHeader('my-header'));
}