static createSafeStyleSheetSecurityPrivateDoNotAccessOrElse(styleSheet) {
    return new SafeStyleSheet(styleSheet, CONSTRUCTOR_TOKEN_PRIVATE);
  }
Package-internal utility method to create SafeStyleSheet instances.

@param {string} styleSheet The string to initialize the SafeStyleSheet
    object with.
@return {!SafeStyleSheet} The initialized SafeStyleSheet object.
@package