'Limit the number of results by each iteration.
This implements the paging functionality of the GCE list methods and
returns this GCEList instance so that results can be chained:
>>> for sublist in GCEList(driver, driver.ex_list_urlmaps).page(2):
...   sublist
[<GCEUrlMap id="..." name="cli-map">,                 <GCEUrlMap id="..." name="lc-map">]
[<GCEUrlMap id="..." name="web-map">]
:keyword  max_results: Maximum number of results to return per
iteration. Defaults to the GCE default of 500.
:type     max_results: ``int``
:return: This :class:`GCEList` instance
:rtype:  :class:`GCEList`'

def page(self, max_results=500):

    self.params['maxResults'] = max_results
    return self
