($node_a: expr, $node_b: expr, (), $fail_backwards: expr, true /* skip last step */, true /* return extra message */) => {
{
let (extra_msg_option, bs_revoke_and_ack) = commitment_signed_dance!($node_a, $node_b, (), $fail_backwards, true, true, true);
($node_a: expr, $node_b: expr, (), $fail_backwards: expr, true /* skip last step */, true /* return extra message */) => {
{
let (extra_msg_option, bs_revoke_and_ack) = commitment_signed_dance!($node_a, $node_b, (), $fail_backwards, true, true, true);