android/guava/src/com/google/common/collect/Iterators.java
public static <T> boolean all(Iterator<T> iterator, Predicate<? super T> predicate) {
    checkNotNull(predicate);
    while (iterator.hasNext()) {
      T element = iterator.next();
      if (!predicate.apply(element)) {
        return false;
      }
    }
    return true;
  }
public static <T> boolean all(Iterator<T> iterator, Predicate<? super T> predicate) {
    checkNotNull(predicate);
    while (iterator.hasNext()) {
      T element = iterator.next();
      if (!predicate.apply(element)) {
        return false;
      }
    }
    return true;
  }
Returns {@code true} if every element returned by {@code iterator} satisfies the given
predicate. If {@code iterator} is empty, {@code true} is returned.