_setProperty(propertyName, value, propertyType) {
    let propertyChecksPassed = this._checkProperty(
      propertyName,
      value,
      [this._checkUndefined, this._createTypeCheck(propertyType)]);

    if (propertyChecksPassed) {
      this[propertyName] = value;
    }

    return propertyChecksPassed;
  }
Set a property with normal undefined and type-checks