def postinit(self, target, annotation, simple, value=None):
        """Do some setup after initialisation.

        :param target: What is being assigned to.
        :type target: NodeNG

        :param annotation: The type annotation of what is being assigned to.
        :type: NodeNG

        :param simple: Whether :attr:`target` is a pure name
            or a complex statement.
        :type simple: int

        :param value: The value being assigned to the variables.
        :type: NodeNG or None
        """
        self.target = target
        self.annotation = annotation
        self.value = value
        self.simple = simple