IntentionPreviewInfo (@NotNull Project project, @NotNull Editor editor, @NotNull PsiFile file) { PsiMethod method = methodPtr.getElement(); if (method == null) { return IntentionPreviewInfo.EMPTY; } if (!(getStartElement() instanceof PsiMethod superMethod)) { return IntentionPreviewInfo.EMPTY; } List<ParameterInfoImpl> infos = getParameterInfos(superMethod, method); String before = getMethodDescription(method, null); String after = getMethodDescription(method, infos); if (before == null || after == null) { return IntentionPreviewInfo.EMPTY; } return new IntentionPreviewInfo.CustomDiff(JavaFileType.INSTANCE, before, after); }