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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 write_sampler_metadata(self, sampler):
 """Adds writing betas to MultiTemperedMCMCIO. """

        super(EmceePTFile, self).write_sampler_metadata(sampler)
        self[self.sampler_group].attrs["betas"] = sampler.betas