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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def add(self, **kwargs):
 """ Add additional single Variable objects to the Variables object. """

        for name, var in kwargs.items():
            if iskeyword(name):
                var['name'] = name
                name = '_' + name
            if name in self:
                self[name] = merge(self[name], Variable(self.default_type, **var))
            else:
                self[name] = Variable(self.default_type, **var)
        return self