import org.simantics.spreadsheet.SheetCommands;
import org.simantics.spreadsheet.event.model.RemoveCellHandler;
import org.simantics.spreadsheet.resource.SpreadsheetResource;
+import org.simantics.spreadsheet.solver.SheetNode;
+import org.simantics.spreadsheet.solver.SpreadsheetBook;
import org.simantics.ui.selection.WorkbenchSelectionUtils;
import org.simantics.utils.datastructures.Pair;
import org.simantics.utils.strings.AlphanumComparator;