message: allow ack and nack to be destructured
diff: @@ -288,7 +288,7 @@ ConnectionPool.prototype.createMessage = function(connectionId, resp) {
  var milliseconds = parseInt(pt.nanos, 10) / 1e6;
  var originalDataLength = resp.message.data.length;
  - return {
  + var message = {
  connectionId: connectionId,
  ackId: resp.ackId,
  id: resp.message.messageId,
  @@ -300,13 +300,14 @@ ConnectionPool.prototype.createMessage = function(connectionId, resp) {
  get length() {
  return originalDataLength;
  },
  - ack: function() {
  - self.subscription.ack_(this);
  - },
  - nack: function() {
  - self.subscription.nack_(this);
  - },
  };
  + message.ack = function() {
  + self.subscription.ack_(message);
  + };
  + message.nack = function() {
  + self.subscription.nack_(message);
  + };
  + return message;
  };
  /*!
  