List<IndentTransferableData> (@NotNull Transferable content) { IndentTransferableData indentData = new IndentTransferableData(-1); try { final DataFlavor flavor = IndentTransferableData.getDataFlavorStatic(); if (flavor != null) { final Object transferData = content.getTransferData(flavor); if (transferData instanceof IndentTransferableData) { indentData = (IndentTransferableData)transferData; } } } catch (UnsupportedFlavorException | IOException e) { // do nothing } return Collections.singletonList(indentData); }