code: public final Ix<Boolean> sequenceEqual(Iterable<? extends T> other) {
          return sequenceEqual(nullCheck(other, "other is null"), EqualityHelper.INSTANCE);
      }
docs: Determines if two sequences have the same elements in the same order and are the same length based
  on null-safe object equality.
  <p>
  The result's iterator() doesn't support remove().
  @param other the other sequence to compare with
  @return the new Ix instance
  @throws NullPointerException if other is null
  @since 1.0