code: public static PrettyContext getCurrentInstance(final HttpServletRequest request)
     {
        Assert.notNull(request, "HttpServletRequest argument was null");
        PrettyContext prettyContext = (PrettyContext) request.getAttribute(CONTEXT_REQUEST_KEY);
        if (prettyContext instanceof PrettyContext)
        {
           log.trace("Retrieved PrettyContext from Request");
           return prettyContext;
        }
        else
        {
           Assert.notNull(request, "HttpServletRequest argument was null");
           prettyContext = newDetachedInstance(request);
           log.trace("PrettyContext not found in Request - building new instance");
           setCurrentContext(request, prettyContext);
           return prettyContext;
        }
     }
docs: Get the current {@link PrettyContext}, or construct a new one if it does
  not yet exist for this request.
  
  @return current context instance