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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 hash(self):
 """The hash value of the current revision"""

        if 'digest' not in self._p4dict:
            self._p4dict = self._connection.run(['fstat', '-m', '1', '-Ol', self.depotFile])[0]

        return self._p4dict['digest']