{{alias}}( str )
    Creates a MultiSlice object from a comma-separated list of string-serialized
    MultiSlice constructor arguments.

    The function returns `null` if provided an invalid string.

    Parameters
    ----------
    str: string
        Input string containing constructor arguments.

    Returns
    -------
    s: MultiSlice|null
        MultiSlice instance (or null).

    Examples
    --------
    > var s = new {{alias}}( 'null,null,null' );
    > s.data
    [ null, null, null ]
    > s = new {{alias}}( '10,Slice(0,10,1),null' );
    > s.data
    [ 10, <Slice>, null ]

    See Also
    --------