Function command_tree_packet 

pub(crate) fn command_tree_packet<S, R>(
    dispatcher: &CommandDispatcher<S, R>,
    source: &S,
) -> Result<CCommands, CommandTreeProjectionError>
where
    R: CommandRuntime<S>,
    R::Argument: CommandArgumentProtocol,

Builds the command graph visible to one source using vanilla packet indices.