How to use the bs-platform/lib/js/pervasives.js.failwith function in bs-platform

var value;
        if (scheme[0] >= -881134847) {
          value = "Bearer " + (String(scheme[1]) + "");
        } else {
          var match = scheme[1];
          var encoded = Curry._1(Refetch__Utils.btoa, "" + (String(match[0]) + (":" + (String(match[1]) + ""))));
          value = "Basic " + (String(encoded) + "");
        }
        return /* tuple */[
                "Authorization",
                value
              ];
      }
    } else if (variant !== -378039458) {
      if (variant !== 4099528) {
        return Pervasives.failwith("TODO");
      } else {
        var match$1 = param[1];
        return /* tuple */[
                match$1[0],
                match$1[1]
              ];
      }
    } else {
      var match$2 = param[1];
      var typ = match$2[0];
      var typ$1 = typeof typ === "number" ? (
          typ >= -735835133 ? "attachment" : "inline"
        ) : typ[1];
      var value$1 = Rebase.List[/* reduce */3]((function (acc, p) {
              return "" + (String(acc) + ("; " + (String(p) + "")));
            }), typ$1, Rebase.List[/* map */0]((function (param) {

function _pairifyHeader(h) {
  var param = h;
  if (typeof param === "number") {
    return Pervasives.failwith("TODO");
  } else {
    var variant = param[0];
    if (variant >= 246273139) {
      if (variant !== 826042841) {
        if (variant !== 1022564063) {
          if (variant >= 246273140) {
            return Pervasives.failwith("TODO");
          } else {
            return /* tuple */[
                    "Content-Type",
                    param[1]
                  ];
          }
        } else {
          return /* tuple */[
                  "Content-Length",
                  String(param[1])
                ];
        }
      } else {
        var scheme = param[1];
        var value;
        if (scheme[0] >= -881134847) {

}), Resync.Future[/* map */8]((function (param) {
            if (param.tag) {
              return Pervasives.failwith(param[0][/* reason */1]);
            } else {
              return Refetch__Response.body(param[1]);
            }
          }), Refetch.get("http://httpbin.org/image/png")));

case 17 : 
      case 18 : 
      case 19 : 
      case 20 : 
      case 21 : 
      case 22 : 
      case 23 : 
      case 24 : 
      case 25 : 
          return Pervasives.failwith("TODO: exception or option?");
      case 26 : 
          return /* IMUsed */1047445569;
      
    }
  } else {
    return Pervasives.failwith("TODO: exception or option?");
  }
}

function fromRecord(param) {
  var rank = param[/* rank */1];
  switch (param[/* type_ */0]) {
    case "Intelligence" : 
        return /* Intelligence */Block.__(1, [rank]);
    case "Special" : 
        return /* Special */Block.__(2, [rank]);
    case "Strength" : 
        return /* Strength */Block.__(0, [rank]);
    default:
      return Pervasives.failwith("Invalid stat type.");
  }
}

return /* SuiteCycle */Block.__(2, [
                  data.id,
                  makeResult(/* () */0)
                ]);
    case "testCycle" : 
        return /* TestCycle */Block.__(0, [
                  data.id,
                  makeResult(/* () */0)
                ]);
    case "testError" : 
        return /* TestError */Block.__(1, [
                  data.id,
                  data.error
                ]);
    default:
      return Pervasives.failwith("unknown worker message");
  }
}

function handleEventTarget(param) {
  return Pervasives.failwith("Event components are not implemented");
}

function mountEventComponent(param) {
  return Pervasives.failwith("Event components are not implemented");
}

function getChildHostContextForEventTarget(param) {
  return Pervasives.failwith("Event components are not implemented");
}

function getChildHostContextForEventComponent(param) {
  return Pervasives.failwith("Event components are not implemented");
}