public function testAssertArrayMatchingKeysSame()
 {
     MpAssertions::assertArrayMatchingKeysSame(array('k1' => 'v1', 'k2' => 'v2'), array('k2' => 'v2', 'k3' => 'v1'));
     // no matching keys is an empty-empty match
     MpAssertions::assertArrayMatchingKeysSame(array('k1' => 'v1', 'k2' => 'v2'), array('k4' => 'v2', 'k3' => 'v1'));
 }