Updates the dependencies with the given items. Note that this does not reset all previously-evaluated and cached
        nodes.

        :param items: Iterable or dictionary in the format `(dependent_item, dependencies)`.
        :type items: collections.Iterable

def update(self, items):
        """
        Updates the dependencies with the given items. Note that this does not reset all previously-evaluated and cached
        nodes.

        :param items: Iterable or dictionary in the format `(dependent_item, dependencies)`.
        :type items: collections.Iterable
        """
        for item, parents in _iterate_dependencies(items):
            dep = self._deps[item]
            merge_list(dep.parent, parents)