simplify code

diff --git a/contract/tracer.go b/contract/tracer.go
index ccb5917..0e3b230 100644 (file)
--- a/contract/tracer.go
+++ b/contract/tracer.go
@@ -62,10 +62,7 @@ func (t *Tracer) DetachBlock(block *types.Block) error {
        var instances []*Instance
        for _, tx := range block.Transactions {
                inUTXOs, outUTXOs := t.parseTransfer(tx)
-               utxos := outUTXOs
-               if len(outUTXOs) == 0 {
-                       utxos = inUTXOs
-               }
+               utxos := append(outUTXOs, inUTXOs...)
                if len(utxos) == 0 {
                        continue
                }