code: public com.google.appengine.v1.TrafficSplit.ShardBy getShardBy() {
      com.google.appengine.v1.TrafficSplit.ShardBy result = com.google.appengine.v1.TrafficSplit.ShardBy.valueOf(shardBy_);
      return result == null ? com.google.appengine.v1.TrafficSplit.ShardBy.UNRECOGNIZED : result;
    }
docs: <pre>
  Mechanism used to determine which version a request is sent to.
  The traffic selection algorithm will
  be stable for either type until allocations are changed.
  </pre>
  
  <code>.google.appengine.v1.TrafficSplit.ShardBy shard_by = 1;</code>