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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 has_key(self, key):
 """Does the key exist? This method will check to see if it has expired too. """

        if key in self._dict:
            try: 
                self[key]
                return True
            except ValueError:
                return False
            except KeyError:
                return False
        return False