{{alias}}( iterator, hashFcn[, thisArg] )
    Returns an iterator which returns unique values according to a hash
    function.

    A returned iterator internally buffers unique hashes and, thus, has O(N)
    memory requirements.

    An iterated value is considered "unique" if the hash function returns a
    unique hash value for that iterated value. Beware that this *may* result in
    unexpected behavior. Namely, only the first iterated value mapping to a
    particular hash function result is returned, even if subsequent values,
    while mapping to the same hash, are different. Accordingly, iteration order
    *does* matter.

    If an environment supports Symbol.iterator and a provided iterator is
    iterable, the returned iterator is iterable.

    Parameters
    ----------
    iterator: Object
        Input iterator.

    hashFcn: Function
        Hash function.

    thisArg: any (optional)
        Execution context.

    Returns
    -------
    iterator: Object
        Iterator.

    iterator.next(): Function
        Returns an iterator protocol-compliant object containing the next
        iterated value (if one exists) and a boolean flag indicating whether the
        iterator is finished.

    iterator.return( [value] ): Function
        Finishes an iterator and returns a provided value.

    Examples
    --------
    > var it1 = {{alias:@stdlib/array/to-iterator}}( [ 1, 2, 1, 2, 4 ] );
    > function f( v ) { return v.toString(); };
    > var it2 = {{alias}}( it1, f );
    > var v = it2.next().value
    1
    > v = it2.next().value
    2
    > v = it2.next().value
    4
    > var bool = it2.next().done
    true

    See Also
    --------