def __init__(self, calculator):
        """
        @param calculator: The calculator callable that will yield the desired value.
        @type calculator: C{callable}
        """
        if not callable(calculator):
            raise ValueError("Non-callable param: %s" % calculator)
        self.calc = calculator
def __init__ ( self , calculator ) : if not callable ( calculator ) : raise ValueError ( "Non-callable param: %s" % calculator ) self . calc = calculator
@param calculator: The calculator callable that will yield the desired value.
        @type calculator: C{callable}