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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 value(self):
 """Global value."""

        data = clips.data.DataObject(self._env)

        if lib.EnvGetDefglobalValue(
                self._env, self.name.encode(), data.byref) != 1:
            raise CLIPSError(self._env)

        return data.value