IntentionPreviewInfo (@NotNull Project project, @NotNull Editor editor, @NotNull PsiFile file) { final PsiMethod method = PsiTreeUtil.findSameElementInCopy((PsiMethod)getStartElement(), file); PsiTypeElement typeElement = method.getParameterList().getParameters()[myIndex].getTypeElement(); if (typeElement == null) return IntentionPreviewInfo.EMPTY; PsiElementFactory factory = PsiElementFactory.getInstance(project); PsiTypeElement newTypeElement = factory.createTypeElement(myParameterType); typeElement.replace(newTypeElement); return IntentionPreviewInfo.DIFF; }