adding a comment to describe tests

itests/self_sent_txn_test.go

@@ -15,6 +15,10 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+
+// these tests check that the versioned code in vm.transfer is functioning correctly across versions! 
+// we reordered the checks to make sure that a transaction with too much money in it sent to yourself will fail instead of succeeding as a noop
+// more info in this PR! https://github.com/filecoin-project/lotus/pull/7637
 func TestSelfSentTxnV15(t *testing.T) {
 	ctx := context.Background()