File remains unsaved while refactoring

Question

I use the code mentioned below to implement a refactoring for my Xtext DSL.

public WorkspaceEdit executeCommand(Resource resource, Document document, ILanguageServerAccess access,
            ExecuteCommandParams params) {
        WorkspaceEdit edit = createWorkspaceEdit(access, resource.getURI(), document, (Resource copiedResource) -> {
            StatementModel model = (StatementModel) copiedResource.getAllContents().next();
            DecisionTable decisionTable = (DecisionTable) model.getStatement();
            InputClause inputClause = ExpressionFactory.eINSTANCE.createInputClause();
            decisionTable.getInput().add(inputClause);
            PrimitiveValueExpression primitiveValueExpression = ExpressionFactory.eINSTANCE.createPrimitiveValueExpression();
            IntLiteral intLiteral = ExpressionFactory.eINSTANCE.createIntLiteral();
            intLiteral.setValue(1);
            ExpressionWrapper expressionWrapper = ExpressionFactory.eINSTANCE.createExpressionWrapper();
            expressionWrapper.setExpression(primitiveValueExpression);
            inputClause.setExpressionWrapper(expressionWrapper);
            Shape shape1 = MnotationFactory.eINSTANCE.createShape();
            inputClause.setDiagramElement(shape1);
            
        
            

        });
        access.getLanguageClient().applyEdit(new ApplyWorkspaceEditParams(edit, "Remove Xtext! Greeting"));
        return edit;
    }

private WorkspaceEdit createWorkspaceEdit(ILanguageServerAccess access, URI resourceURI, Document document,
            IChangeSerializer.IModification<Resource> mod) {
        ResourceSet rs = access.newLiveScopeResourceSet(resourceURI);
        Resource copy = rs.getResource(resourceURI, true);
        IChangeSerializer serializer = serializerProvider.get();
        EcoreUtil.resolveAll(copy);
        serializer.addModification(copy, mod);
        List<IEmfResourceChange> documentchanges = new ArrayList<>();
        serializer.applyModifications(CollectionBasedAcceptor.of(documentchanges));
        WorkspaceEdit workspaceEdit = new WorkspaceEdit();
        for (ITextDocumentChange documentchange : Iterables.filter(documentchanges, ITextDocumentChange.class)) {
            List<TextEdit> edits = ListExtensions.map(documentchange.getReplacements(),
                    (ITextReplacement replacement) -> {
                        TextEdit textEdit = new TextEdit();
                        textEdit.setNewText(replacement.getReplacementText());
                        textEdit.setRange(new Range(document.getPosition(replacement.getOffset()),
                                document.getPosition(replacement.getEndOffset())));
                        return textEdit;
                    });
            workspaceEdit.getChanges().put(documentchange.getNewURI().toString(), edits);
        }
        return workspaceEdit;
    }

It results the Change in my Xtext DSL but leaves the files open & unsaved in theia-editor.

How can I fix this issue to refactor files without opening them on editor?