private int transferOffsetFromTwoside(@NotNull Side side, int offset) {
      LineCol twosidePosition = LineCol.fromOffset(getDocument(side), offset);

      int onesideLine = transferLineToOneside(side, twosidePosition.line);
      if (onesideLine == -1) return -1;

      LineCol onesidePosition = new LineCol(onesideLine, twosidePosition.column);
      return onesidePosition.toOffset(myDocument);
    }
private int transferOffsetFromTwoside(@NotNull Side side, int offset)