
{{alias}}( [year] )
    Returns the number of ISO weeks in a year according to the Gregorian
    calendar.

    By default, the function returns the number of ISO weeks in the current year
    (according to local time). To determine the number of ISO weeks for a
    particular year, provide either a year or a `Date` object.

    Parameters
    ----------
    year: integer (optional)
        Year.

    Returns
    -------
    out: integer
        Number of ISO weeks in a year.

    Examples
    --------
    > var num = {{alias}}()
    <number>
    > num = {{alias}}( 2015 )
    53
    > num = {{alias}}( 2017 )
    52

    See Also
    --------

