new \Twig_Environment(ne...g' => 'Hello World!'))) of type object<Twig_Environment> is not a sub-type of object<Twig\Environment>. It seems like you assume a child class of the class Twig_Environment to be always present.
This check looks for parameters that are defined as one type in their type
hint or doc comment but seem to be used as a narrower type, i.e an
implementation of an interface or a subclass.
Consider changing the type of the parameter or doing an instanceof check before assuming
your parameter is of the expected type.
You can fix this by adding a namespace to your class:
When choosing a vendor namespace, try to pick something that is not too generic to avoid conflicts with other libraries.