A wrapper around HttpServletRequest, associated with a given scope-key. All calls to setAttribute,
getAttribute, removeAttribute, etc. are scoped to this object, while most other functionality
delegates to the wrapped HttpServletRequest.
Instances of this class also keep track of their own request-URIs, which are independent of the
wrapped request-URIs.
getAttribute(String attrName, boolean allowOuterRequestAttributes) Same as getAttribute, but allows outer request attributes to be hidden explicitly, even if the implementation
of getAttribute shows them by default.