function makePrintable() {
  var hintInfo = [];

  for (var _i = 0; _i < arguments.length; _i++) {
    hintInfo[_i] = arguments[_i];
  }

  var msg = '';

  if (true) {
    // Fuzzy stringify for print.
    // This code only exist in dev environment.
    var makePrintableStringIfPossible_1 = function (val) {
      return val === void 0 ? 'undefined' : val === Infinity ? 'Infinity' : val === -Infinity ? '-Infinity' : eqNaN(val) ? 'NaN' : val instanceof Date ? 'Date(' + val.toISOString() + ')' : isFunction(val) ? 'function () { ... }' : isRegExp(val) ? val + '' : null;
    };

    msg = map(hintInfo, function (arg) {
      if (isString(arg)) {
        // Print without quotation mark for some statement.
        return arg;
      } else {
        var printableStr = makePrintableStringIfPossible_1(arg);

        if (printableStr != null) {
          return printableStr;
        } else if (typeof JSON !== 'undefined' && JSON.stringify) {
          try {
            return JSON.stringify(arg, function (n, val) {
              var printableStr = makePrintableStringIfPossible_1(val);
              return printableStr == null ? val : printableStr;
            }); // In most cases the info object is small, so do not line break.
          } catch (err) {
            return '?';
          }
        } else {
          return '?';
        }
      }
    }).join(' ');
  }

  return msg;
}
If in __DEV__ environment, get console printable message for users hint.
Parameters are separated by ' '.
@usuage
makePrintable('This is an error on', someVar, someObj);

@param hintInfo anything about the current execution context to hint users.
@throws Error