Improve `MarkNewHeaviestPreflight` docs
@@ -56,7 +56,8 @@ type Relay interface {
// MarkNewHeaviestPreflight performs a preflight call of the
// MarkNewHeaviest method to check whether its execution will
- // succeed.
+ // succeed. If the preflight call was successful, `true` is returned.
+ // In case the preflight returns an error, `false` is returned.
MarkNewHeaviestPreflight(
ancestorDigest [32]byte,
currentBestHeader []byte,
