def reverse(arr, b):
    """Reverse elements in a list.

    This function is equivalent to:

    .. code-block:: javascript

       function(a, b) { a.reverse() }

    This method takes an unused ``b`` variable as their transform functions
    universally sent two arguments.

    **Example**:

    >>> reverse([1, 2, 3, 4])
    [4, 3, 2, 1]
    """
    return arr[::-1]
