/// <summary>
/// Sends a string message to a specified topic with headers.
///
/// There will be no context with the message so callback will be directed to the 'no context' callback.
/// </summary>
/// <param name="topicPath">The topic path.</param>
/// <param name="message">The message to send.</param>
/// <param name="headers">The headers to send with the message.</param>
/// <param name="callback">Notifies that the message was sent.</param>
public void SendWithHeaders(string topicPath, string message, List <string> headers, ISendCallback callback)
{
messaging.Send(
topicPath,
Diffusion.Content.NewContent(message),
messaging.CreateSendOptionsBuilder().SetHeaders(headers).Build(),
callback);
}