fix generics

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/proxy/trunk@1582521 13f79535-47bb-0310-9956-ffa450edef68
unmodifiable static maps

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/proxy/trunk@1582522 13f79535-47bb-0310-9956-ffa450edef68