Java Utililty Methods Iterable First

return equal(first.iterator(), second.iterator());

if (null == iterable) {
    return null;
final Iterator<E> it = iterable.iterator();
if (!it.hasNext()) {
    return null;
return it.next();
...

return iter == null ? null : next(iter.iterator());

return first(iterable.iterator());

Iterator<E> iterator = i.iterator();
if (!iterator.hasNext()) {
    throw new IllegalArgumentException("iterator has no elements");
return iterator.next();

return first(iterable.iterator(), null);

if (iterable instanceof Deque<?>)
    return ((Deque<T>) iterable).getFirst();
if (iterable instanceof List<?>) {
    List<T> list = (List<T>) iterable;
    return list.isEmpty() ? null : list.get(0);
Iterator<T> iterator = iterable.iterator();
return iterator.hasNext() ? iterator.next() : null;
...

final int indexPosition = 0;
return elementAt(iterable, indexPosition);

Iterator iterator = iterable.iterator();
if (iterator.hasNext()) {
    return iterator.next();
} else {
    return null;

return nthOf(iterable, 0);