/// Send an empty onion message to `destination`, routing it through `intermediate_nodes`.
/// See [`OnionMessenger`] for example usage.
pub fn send_onion_message(&self, intermediate_nodes: &[PublicKey], destination: Destination) -> Result<(), SendError> {
/// Send an empty onion message to `destination`, routing it through `intermediate_nodes`.
/// See [`OnionMessenger`] for example usage.
pub fn send_onion_message(&self, intermediate_nodes: &[PublicKey], destination: Destination) -> Result<(), SendError> {