public  void destroy() 
{
    //Destroy filter services
    for(Filter f:_filters)
    {
      f.destroy();
    }
    _filters = null;
}

 public  void doFilter(ServletRequest request,
    ServletResponse response,
    FilterChain chain) throws IOException, ServletException 
{
    //Execute the filter services
    if (!_filters.isEmpty())
      chain = new FilterListChain(_filters, chain);
    // Set a flag so that we can detect if the filter has been
    // properly installed.
    request.setAttribute(_FILTER_EXECUTED_KEY, Boolean.TRUE);
    ExternalContext externalContext = new ServletExternalContext(_servletContext, request, response);    
    GlobalConfiguratorImpl config = GlobalConfiguratorImpl.getInstance();
    config.beginRequest(externalContext);
    //To maintain backward compatibilty, wrap the request at the filter level
    Map< String, String[] > addedParams = FileUploadConfiguratorImpl.getAddedParameters(externalContext);
    if(addedParams != null)
    {
      FileUploadConfiguratorImpl.apply(externalContext);
      request = new UploadRequestWrapper((HttpServletRequest)request, addedParams);
    }
    try
    {
      _doFilterImpl(request, response, chain);
    }
    // For PPR errors, handle the request specially
    catch (Throwable t)
    {
      boolean isPartialRequest;
      if (addedParams != null)
      {
        isPartialRequest = CoreRenderKit.isPartialRequest(addedParams);
      }
      else
      {
        isPartialRequest = CoreRenderKit.isPartialRequest(externalContext);
      }
      if (isPartialRequest)
      {
        XmlHttpConfigurator.handleError(externalContext, t);
      }
      else
      {
        // For non-partial requests, just re-throw.  It is not
        // our responsibility to catch these
        if (t instanceof RuntimeException)
          throw ((RuntimeException) t);
        if (t instanceof Error)
          throw ((Error) t);
        if (t instanceof IOException)
          throw ((IOException) t);
        if (t instanceof ServletException)
          throw ((ServletException) t);
        // Should always be one of those four types to have
        // gotten here.
        _LOG.severe(t);
      }
    }
    finally
    {
      config.endRequest(externalContext);
    }
}

 public static FacesContext getPseudoFacesContext() 
{
    return _PSEUDO_FACES_CONTEXT.get();
}

 public  void init(FilterConfig filterConfig) throws ServletException 
{
    _servletContext = filterConfig.getServletContext();
    //There is some functionality that still might require servlet-only filter services.
    _filters = ClassLoaderUtils.getServices(TrinidadFilterImpl.class.getName());
    for(Filter f:_filters)
    {
      f.init(filterConfig);
    }
}

 public static boolean isExecutingDialogReturn(FacesContext context) 
{
    return Boolean.TRUE.equals(
      context.getExternalContext().getRequestMap().get(_IS_RETURNING_KEY));
}

Returns true if the filter is in the middle of executing the "return from dialog"

 public static  void verifyFilterIsInstalled(FacesContext context) 
{
    Object isInstalled =
      context.getExternalContext().getRequestMap().get(_FILTER_EXECUTED_KEY);
    if (!Boolean.TRUE.equals(isInstalled))
    {
      _LOG.warning("REQUIRED_TRINIDADFILTER_NOT_INSTALLED");
    }
}