code: public static SObject of(String key, File file, String... attrs) {
          SObject sobj = of(key, $.requireNotNull(file));
          Map<String, String> map = C.Map(attrs);
          sobj.setAttributes(map);
          return sobj;
      }
docs: Construct an SObject with key, file and attributes specified in
  key1, val1, key2, val2... sequence
  
  @see #of(String, File, Map)