Service with no endpoints), the underlying implementation MUST actively
                        reject connection attempts to this backend. Connection rejections must
                        respect weight; if an invalid backend is requested to have 80% of
                        connections, then 80% of connections must be rejected instead.

Outputs random values from the Gamma distribution(s) described by alpha.
  }];

  let description = [{
This op uses the algorithm by Marsaglia et al. to acquire samples via
transformation-rejection from pairs of uniform and normal random variables.
See http://dl.acm.org/citation.cfm?id=358414
  }];

  let arguments = (ins