/*
    Creates a new <objj>CPString</objj> from the concatenation of the receiver and the specified format and arguments in the manner of stringWithFormat:.
    @param format the format, printf-style to append to the receiver,
    @return the new string
*/
- (CPString)stringByAppendingFormat:(CPString)format, ...
{
    if (!format)
        [CPException raise:CPInvalidArgumentException
                    reason:"stringByAppendingFormat: the format can't be 'nil'"];

    return self + sprintf.apply(this, Array.prototype.slice.call(arguments, 2));

}