getMock('Zend_Http_UserAgent_Mobile'); $reflection_class = new ReflectionClass("Zend_Http_UserAgent_Mobile"); $property = $reflection_class->getProperty('_uaSignatures'); $property->setAccessible(true); $uaSignatures = $property->getValue($stub); $result = array_diff_key($uaSignatures, array_unique($uaSignatures, SORT_STRING)); $this->assertEmpty($result); } }