@Override
 public FilterRegistration getFilterRegistration(String filterName) {
   if (SecurityUtil.isPackageProtectionEnabled()) {
     return (FilterRegistration) doPrivileged("getFilterRegistration", new Object[] {filterName});
   } else {
     return context.getFilterRegistration(filterName);
   }
 }
 /** Gets the FilterRegistration corresponding to the filter with the given <tt>filterName</tt>. */
 @Override
 @SuppressWarnings("unchecked") // doPrivileged() returns the correct type
 public FilterRegistration getFilterRegistration(String filterName) {
   if (SecurityUtil.isPackageProtectionEnabled()) {
     return (FilterRegistration) doPrivileged("getFilterRegistration", new Object[] {filterName});
   } else {
     return context.getFilterRegistration(filterName);
   }
 }