Set the value of the option.
        
        One can also set the 'value' property:

        >>> opt = ValueOption("oname", Numeric(default=1,help="an option exemple"))
        >>> opt.value = 12
        
        :param value: the new value

def set(self, value, parse=False):
        """ Set the value of the option.
        
        One can also set the 'value' property:

        >>> opt = ValueOption("oname", Numeric(default=1,help="an option exemple"))
        >>> opt.value = 12
        
        :param value: the new value
        """
        self.value = self.parse(value) if parse else value