}
public Expression handleExpression(HiddenTokenAwareTree token) {
LinkedList<HiddenTokenAwareTree> children = new LinkedList<HiddenTokenAwareTree>(token.getChildren());
if (children.size() == 0)
throw new BugHappened(GRAMMAR_MISMATCH, token);
if (children.size() == 1) {
Expression head = (Expression) switchOn(children.get(0));
// we have to switch to parent token, because we would loose it otherwise.
// for example, comments before simple expressions would not be accessible