Better comments

store/state.go

@@ -27,17 +27,24 @@ func IsStaleRead(
 	strict bool,
 ) bool {
 	if freshness == 0 {
+		// Freshness not set, so no read can be stale.
 		return false
 	}
 	if time.Since(leaderlastContact).Nanoseconds() > freshness {
+		// The Leader has not been in contact witin the freshness window, so
+		// the read is stale.
 		return true
 	}
 	if !strict {
+		// Strict mode is not enabled, so no further checks are needed.
 		return false
 	}
 	if fsmIndex == commitIndex {
+		// FSM index is the same as the commit index, so we're caught up.
 		return false
 	}
+	// OK, we're not caught up. So was the log that last updated our local FSM
+	// appended by the Leader to its log within the freshness window?
 	return lastFSMUpdateTime.Sub(lastAppendedAtTime).Nanoseconds() > freshness
 }