public function testRegisterDatatypeAlias()
 {
     DataValueFactory::registerDatatypeAlias('_foo', 'Bar');
     $this->assertEquals('_foo', DataValueFactory::findTypeID('Bar'));
     DataValueFactory::getInstance()->registerDatatypeAlias('_foo', 'Bar');
     $this->assertEquals('_foo', DataValueFactory::getInstance()->findTypeID('Bar'));
 }