Comment by sethvargo

Also, this isn't semantically correct. In order to ensure that `conditionaA` is _always_ preferred over `conditionB`, you must also check if `conditionA` has received a value inside of `conditionB`:

    select {
    case a := <-conditionA:
        return a
    default:
    }
    select {
    case b := <-conditionB:
      case a := <-conditionA:
          return a
      default:

      return b
    default:
    }