doUnPrepare method

Implementation

void doUnPrepare() {
  if (_cursor != null) {
    if (_database != null) {
      _database!.unPrepareStatement(_cursor!);
      deAllocateCursor();
    } else {
      // this should never happen. It means a cursor handle leaks in
      // the DB itself. (original comment kept as-is)
      _cursor = null;
    }
  }
}