Return all instances of this class and subclasses

        :returns: all instances of the current class and subclasses
        :rtype: list
        :raises: None

def instances(cls):
        """Return all instances of this class and subclasses

        :returns: all instances of the current class and subclasses
        :rtype: list
        :raises: None
        """
        l = [i for i in cls.allinstances() if isinstance(i, cls)]
        return l