@Override
 public void invoke(@NotNull Project project, Editor editor, @NotNull PsiElement element)
     throws IncorrectOperationException {
   if (!FileModificationService.getInstance().preparePsiElementsForWrite(element)) return;
   final XmlAttribute attr = (XmlAttribute) element.getParent();
   final String name = attr.getName();
   final XmlAttributeDescriptor descriptor = attr.getDescriptor();
   LOG.assertTrue(descriptor != null);
   String value = attr.getValue();
   final PsiElement declaration = descriptor.getDeclaration();
   if (declaration instanceof PsiField) {
     final PsiType fieldType = ((PsiField) declaration).getType();
     final PsiType itemType =
         JavaGenericsUtil.getCollectionItemType(fieldType, declaration.getResolveScope());
     if (itemType != null) {
       final String typeNode = itemType.getPresentableText();
       JavaFxPsiUtil.insertImportWhenNeeded(
           (XmlFile) attr.getContainingFile(), typeNode, itemType.getCanonicalText());
       final String[] vals = value.split(",");
       value =
           StringUtil.join(
               vals,
               new Function<String, String>() {
                 @Override
                 public String fun(String s) {
                   return "<"
                       + typeNode
                       + " "
                       + FxmlConstants.FX_VALUE
                       + "=\""
                       + s.trim()
                       + "\"/>";
                 }
               },
               "\n");
     }
   }
   final XmlTag childTag =
       XmlElementFactory.getInstance(project)
           .createTagFromText("<" + name + ">" + value + "</" + name + ">");
   attr.getParent().add(childTag);
   attr.delete();
 }
  public PsiFile[] getRelatedFiles(final XPathFile file) {

    final XmlAttribute attribute = PsiTreeUtil.getContextOfType(file, XmlAttribute.class, false);
    assert attribute != null;

    final PsiFile psiFile = attribute.getContainingFile();
    assert psiFile != null;

    final List<PsiFile> files = new ArrayList<PsiFile>();

    psiFile.accept(
        new XmlRecursiveElementVisitor() {
          @Override
          public void visitXmlAttribute(XmlAttribute attribute) {
            final PsiFile[] _files = XsltSupport.getFiles(attribute);
            for (PsiFile _file : _files) {
              if (_file != file) files.add(_file);
            }
          }
        });

    return PsiUtilCore.toPsiFileArray(files);
  }