public LocalsArray subArrayForLabel(int subLabel) {
    LocalsArray result = getSecondaryForLabel(subLabel);
    return result;
  }
Returns a LocalsArray instance representing the locals state that should be used when returning
to a subroutine caller.

@param subLabel {@code >= 0;} A calling label of a subroutine
@return {@code null-ok;} an instance for this subroutine, or null if subroutine is not in this
    set.
android/android_framework/dex-maker/src/main/java/com/android/dx/cf/code/LocalsArraySet.java