List<ExceptionProblem> (PsiExpression expression) { List<ExceptionProblem> problems = new ArrayList<>(); for (Function<PsiExpression, ExceptionProblem> extractor : PROBLEM_EXTRACTORS) { ExceptionProblem exceptionProblem = extractor.apply(expression); if (exceptionProblem != null) { problems.add(exceptionProblem); } } return problems; }