37      case Hal::TwoTrack::PairType::kSignal: {
 
   42      case Hal::TwoTrack::PairType::kBackground: {
 
   47      case Hal::TwoTrack::PairType::kMixed: {
 
   52      case Hal::TwoTrack::PairType::kRotated: {
 
   57      case Hal::TwoTrack::PairType::kHemishpere: {
 
   62      case Hal::TwoTrack::PairType::kOther: {