void (@NotNull PsiLambdaExpression expression) { List<PsiTypeElement> typeElements = new ArrayList<>(); for (PsiParameter parameter: expression.getParameterList().getParameters()) { PsiTypeElement typeElement = getTypeElementToExpand(parameter); if (typeElement == null) return; typeElements.add(typeElement); } for (PsiTypeElement typeElement: typeElements) { registerTypeElementProblem(typeElement); } }