'Wrap a list method in a :class:`GCEList` iterator.
>>> for sublist in driver.ex_list(driver.ex_list_urlmaps).page(1):
...   sublist
[<GCEUrlMap id="..." name="cli-map">]
[<GCEUrlMap id="..." name="lc-map">]
[<GCEUrlMap id="..." name="web-map">]
:param  list_fn: A bound list method from :class:`GCENodeDriver`.
:type   list_fn: ``instancemethod``
:return: An iterator that returns sublists from list_fn.
:rtype: :class:`GCEList`'

def ex_list(self, list_fn, **kwargs):

    return GCEList(driver=self, list_fn=list_fn, **kwargs)
