code: public ArchEnum getArch() {
      if (isReference()) {
        final TargetDef refPlatform = (TargetDef) getCheckedRef(TargetDef.class, "TargetDef");
        return refPlatform.getArch();
      }
      return this.arch;
    }
docs: Gets arch.
  
  @return arch, may be null.