public function testimplodeAssociativeArray()
{
$array = ['test1' => 'val1', 'test2' => 'val2', 'test3' => new DateTime('2015-05-15 17:21:00')];
$string = Braintree\Util::implodeAssociativeArray($array);
$this->assertEquals('test1=val1, test2=val2, test3=Fri, 15 May 2015 17:21:00 +0000', $string);
}