code: @Nullable
    public static Cookie [] getRequestCookies (@Nullable final HttpServletRequest aRequest)
    {
      Cookie [] ret = null;
      if (aRequest != null)
        try
        {
          ret = aRequest.getCookies ();
        }
        catch (final Exception ex)
        {
          // fall through
          if (isLogExceptions ())
            if (LOGGER.isWarnEnabled ())
              LOGGER.warn ("[ServletHelper] Failed to determine cookies of HTTP request", ex);
        }
      return ret;
    }
docs: Work around an exception that can occur on Tomcat 8.0.20:
  
  <pre>
  java.lang.NullPointerException: null
  at org.apache.catalina.connector.Request.parseCookies(Request.java:2943) ~[catalina.jar:8.0.20]
  at org.apache.catalina.connector.Request.convertCookies(Request.java:2958) ~[catalina.jar:8.0.20]
  at org.apache.catalina.connector.Request.getCookies(Request.java:1987) ~[catalina.jar:8.0.20]
  at org.apache.catalina.connector.RequestFacade.getCookies(RequestFacade.java:662) ~[catalina.jar:8.0.20]
  </pre>
  
  @param aRequest
  Source request. May be <code>null</code>.
  @return getRequestCookies