'Constructor.
Args:
response_proto: the URLFetchResponse proto buffer to wrap.'

def __init__(self, response_proto):

    self.__pb = response_proto
    self.content = response_proto.content()
    self.status_code = response_proto.statuscode()
    self.content_was_truncated = response_proto.contentwastruncated()
    self.final_url = (response_proto.finalurl() or None)
    self.header_msg = httplib.HTTPMessage(StringIO.StringIO(''.join(([('%s:    %s\n' % (h.key(), h.value())) for h in response_proto.header_list()] + ['\n']))))
    self.headers = _CaselessDict(self.header_msg.items())
