use bitcoin::secp256k1::Error as SecpError;
use bitcoin::secp256k1;
-use std::cmp;
+use core::cmp;
use ln::chan_utils;
use util::transaction_utils::sort_outputs;
use ln::channel::INITIAL_COMMITMENT_NUMBER;
use std::io::Read;
-use std::ops::Deref;
+use core::ops::Deref;
use chain;
// Maximum size of a serialized HTLCOutputInCommitment