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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):
 """Writes the sampler's metadata."""

        self.attrs['sampler'] = sampler.name
        self[self.sampler_group].attrs['nwalkers'] = sampler.nwalkers
        # write the model's metadata
        sampler.model.write_metadata(self)