'Check if the new app version is ready to serve traffic.
Raises:
RuntimeError: Deploy has not yet been called.
Returns:
True if the server returned the app is ready to serve.'

def IsReady(self):

    assert self.deployed, 'Deploy()    must    be    called    before    IsReady().'
    StatusUpdate('Checking    if    deployment    succeeded.', self.error_fh)
    result = self.logging_context.Send('/api/appversion/isready')
    return (result == '1')
