private ResourceMap getMap() {
        ResourceMap resourceMap;

        final HttpServletRequest request = httpServletRequestHolder.get();
        if (request == null) {
            throw new NullPointerException("Request holder has no current request");
        }

        final String name = "SESSION_RESOURCE_STORE";
        final HttpSession session = request.getSession();
        final Object object = session.getAttribute(name);
        if (object == null) {
            resourceMap = new ResourceMap();
            session.setAttribute(name, resourceMap);
        } else {
            resourceMap = (ResourceMap) object;
        }

        return resourceMap;
    }
Wrapper for the ResourceStore that makes sure the user can only access stuff
in the session.
stroom-resource/stroom-resource-impl/src/main/java/stroom/resource/impl/SessionResourceStoreImpl.java