Collection<PyExpression> () { final PyExpression[] arguments = getArguments(); final Collection<PyExpression> result = new ArrayList<>(arguments.length); for (final PyExpression expression : arguments) { if (expression instanceof PyKeywordArgument) { final PyExpression valueExpression = ((PyKeywordArgument)expression).getValueExpression(); result.add(valueExpression); } if (expression instanceof PyReferenceExpression) { result.add(expression); } } return result; }