pub fn one_hop_for_message<ES: Deref, T: secp256k1::Signing + secp256k1::Verification>(
recipient_node_id: PublicKey, entropy_source: ES, secp_ctx: &Secp256k1<T>
) -> Result<Self, ()> where ES::Target: EntropySource {
pub fn one_hop_for_message<ES: Deref, T: secp256k1::Signing + secp256k1::Verification>(
recipient_node_id: PublicKey, entropy_source: ES, secp_ctx: &Secp256k1<T>
) -> Result<Self, ()> where ES::Target: EntropySource {