void (final DomFileElement<IdeaPlugin> selectedValue, final Project project, final PsiFile file) { Extension extension = WriteCommandAction.writeCommandAction(project, file).compute(() -> { final Extensions extensions = PluginDescriptorChooser.findOrCreateExtensionsForEP(selectedValue, myEp.getName()); Extension e = extensions.addExtension(myEp.getName()); XmlTag tag = e.getXmlTag(); tag.setAttribute("implementationClass", myPsiClass.getQualifiedName()); tag.setAttribute("language", ""); return e; }); PsiNavigateUtil.navigate(extension.getXmlTag()); }