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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 accessor(self):
 """Get an attribute's accessor with the getter and the setter. :return: `Accessor` instance. """

        if isinstance(self.attr, Accessor):
            return self.attr

        if callable(self.attr):
            return Accessor(getter=self.attr)

        attr = self.attr or self.name
        return Accessor(getter=attr, setter=attr)