@staticmethod
def _get_next_marker_from_response_object(response_object):
    """Get the marker that should be used to retrieve the next page.

        When we've just retrieved the last page, the API is inconsistent about
        what it returns. Some endpoints return "next_marker":"", some return
        "next_marker":null, some don't give any "next_marker" value. In all of
        these cases, this method will return `None`.

        Otherwise, this method returns the string value of the "next_marker"
        field.

        :rtype:
            `unicode` or `None`
        """
    return response_object.get('next_marker') or None
