public function testInstanceMetadata()
{
$expected_path = 'instance/attributes/mykey';
$expected_val = 'myval';
$this->mock->expects($this->once())->method('read')->with($this->equalTo($expected_path))->willReturn($expected_val);
$val = $this->metadata->getInstanceMetadata('mykey');
$this->assertEquals($expected_val, $val);
}