Is PreparedSqlLiteInsertCommand::executeNonQuery thread safe?

[edolphin-ydf]

Thanks for the execllent plugin.
I use it in a multi thread environment. I'v met a crash which point to executeNonQuery in both PreparedSqlLiteInsertCommand and SQLiteCommandclass in two different thread.
After view the code, i found that the sqlite operations were locked with _conn.SyncObject in SQLiteCommand::executeNonQuery, but it doesn't in PreparedSqlLiteInsertCommand::executeNonQuery . Were this intended or a bug？If it's ok，then why？