def clone(self, updates={}):
    'Clone ``self`` and update specified options. '
    obj = dict.__new__(self.__class__)
    for (option, value) in self.items():
        obj[option] = value
    for (option, value) in updates.items():
        obj[option] = value
    return obj
Clone ``self`` and update specified options.
def clone(self, updates={}):
    ' '
    obj = dict.__new__(self.__class__)
    for (option, value) in self.items():
        obj[option] = value
    for (option, value) in updates.items():
        obj[option] = value
    return obj