Get index of the parameter.
        :param item: Item for which get the index.
        :return: Index of the parameter in the WeakList.

def index(self, item, **kwargs):
        # type: (Any, dict) -> int
        """
        Get index of the parameter.
        :param item: Item for which get the index.
        :return: Index of the parameter in the WeakList.
        """
        return list.index(self, self.ref(item), **kwargs)