chainreg: satisfy chain.Interface in NoChainSource

chainreg/no_chain_backend.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"time"
 
+	"github.com/btcsuite/btcd/btcjson"
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/wire"
@@ -213,4 +214,10 @@ func (n *NoChainSource) BackEnd() string {
 	return noChainBackendName
 }
 
+func (n *NoChainSource) TestMempoolAccept([]*wire.MsgTx,
+	float64) ([]*btcjson.TestMempoolAcceptResult, error) {
+
+	return nil, nil
+}
+
 var _ chain.Interface = (*NoChainSource)(nil)