'PATCH updates the location of the proxy
Can be used to notify the Hub that a new proxy is in charge'

@admin_only
@gen.coroutine
def patch(self):

    if (not self.request.body):
        raise web.HTTPError(400, 'need    JSON    body')
    try:
        model = json.loads(self.request.body.decode('utf8', 'replace'))
    except ValueError:
        raise web.HTTPError(400, 'Request    body    must    be    JSON    dict')
    if (not isinstance(model, dict)):
        raise web.HTTPError(400, 'Request    body    must    be    JSON    dict')
    if ('api_url' in model):
        self.proxy.api_url = model['api_url']
    if ('auth_token' in model):
        self.proxy.auth_token = model['auth_token']
    self.log.info('Updated    proxy    at    %s', self.proxy)
    (yield self.proxy.check_routes(self.users, self.services))
