code: @Override
      public Object getMember(String name) {
          switch (name) {
              case "_1": return F_1;
              case "_2": return F_2;
              case "_3": return F_3;
              case "_4": return F_4;
              case "_5": return F_5;
          }
          return super.getMember(name);
      }
docs: get the value of that named property