diff --git a/lib/TransactionBuilder.js b/lib/TransactionBuilder.js
index bebc322..dbf46d4 100644
--- a/lib/TransactionBuilder.js
+++ b/lib/TransactionBuilder.js
@@ -926,6 +926,7 @@ TransactionBuilder.prototype._checkMergeability = function(b) {
 
 };
 
+// TODO this could be on Script class
 TransactionBuilder.prototype._mergeInputSigP2sh = function(input,s0,s1) {
   var p2sh  = this._p2shInput(input);
   var redeemScript = new Script(p2sh.scriptBuf);
@@ -963,6 +964,7 @@ TransactionBuilder.prototype._mergeInputSigP2sh = function(input,s0,s1) {
   return s0.getBuffer();
 };
 
+// TODO this could be on Script class
 TransactionBuilder.prototype._mergeInputSig = function(index, s0buf, s1buf) {
   if (buffertools.compare(s0buf,s1buf) === 0)
     return s0buf;
@@ -996,7 +998,8 @@ TransactionBuilder.prototype._mergeInputSig = function(index, s0buf, s1buf) {
   return this._mergeInputSigP2sh(input,s0, s1);
 };
 
-TransactionBuilder.prototype._mergeTx = function(tx, ignoreConflictingSignatures) {
+// TODO this could be on Transaction class
+TransactionBuilder.prototype._mergeTx = function(tx) {
     var v0 = this.tx;
     var v1 = tx;