protected String buildActualTypedAltArgumentList(Iterator<Field> fields,
boolean convertBuiltins) {
StringBuffer buf = new StringBuffer();
while (fields.hasNext()) {
Field field = fields.next();
String field_id = getFieldId(field.getId());
String field_type = field.getType();
if (convertBuiltins) {
field_id = getConverter().makeBuiltinToATermConversion(
field_type, field_id);
}