setmessagePropertyFromHeaders = function (messageProperty, headerProperty) {
    if (!self[messageProperty] && headers[headerProperty.toLowerCase()]) {
      self[messageProperty] = headers[headerProperty.toLowerCase()];
    }
  }
Pase the XML representation of a queue message to a QueueMessageResult object.

@param  {Object}  messageXml   The XML representation of the queue message.
@param  {QueueMessageEncoder}  The message encoder.
@return {QueueMessageResult}   The QueueMessageResult object.