code: def update_hparams_from_hparams(target_hparams, source_hparams, prefix):
    
    for (param_name, param_value) in six.iteritems(source_hparams.values()):
      if param_name.startswith(prefix):
        target_hparams.set_hparam(param_name[len(prefix):], param_value)
docs: Copy a subset of hparams to target_hparams.