any method
override
    Checks whether any element of this iterable satisfies test.
Checks every element in iteration order, and returns true if
any of them make test return true, otherwise returns false.
Implementation
bool any(bool test(E element)) {
  int length = this.length;
  for (int i = 0; i < length; i++) {
    if (test(this[i])) return true;
    if (length != this.length) {
      throw new ConcurrentModificationError(this);
    }
  }
  return false;
}