isEqualTo(other, comparator = (e1, e2) => e1 === e2) {
        if (!isIterable(other)) {
            return false;
        }
        if (other === this) {
            return true;
        }
        let iter2 = other[Symbol.iterator]();
        for (let e1 of this._iterable) {
            let e2 = iter2.next();
            if (e2.done || !comparator(e1, e2.value)) {
                return false;
            }
        }
        return iter2.next().done;
    }
Determines if the given iterable contains the same items as this sequence.
@param {*|!(T[])|!Seq.<T>|!Iterable.<T>} other
@param {!function(T, T|*) : !boolean} comparator
@template T