code: public static alluxio.grpc.LocalityTier toProto(TieredIdentity.LocalityTier localityTier) {
      alluxio.grpc.LocalityTier.Builder tier =
          alluxio.grpc.LocalityTier.newBuilder().setTierName(localityTier.getTierName());
      if (localityTier.getValue() != null) {
        tier.setValue(localityTier.getValue());
      }
      return tier.build();
    }
docs: Converts wire type to proto type.
  
  @param localityTier the wire representation to convert
  @return converted proto representation