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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 timeshift(self):
 """Return if the stream is a timeshift."""

        if self.tune and self.tune.get('@src'):
            return True if self.tune.get('@src').startswith('timeshift') else False
        else:
            raise PyMediaroomError("No information in <node> about @src")