public void cachedJs(Permutation permutation, final String resourceUrn) {
   getEntry(permutation.toExternal()).m_cachedJsUrns.add(resourceUrn);
 }
 public Set<String> getCachedJsSet(final Permutation permutation) {
   return getEntry(permutation.toExternal()).m_cachedJsUrns;
 }
 public boolean isCached(final Permutation permutation) {
   return m_caches.containsKey(permutation.toExternal());
 }
 public Iterable<String> getJsSlotNames(final Permutation permutation) {
   return getEntry(permutation.toExternal()).m_slottedJsRef.keySet();
 }
 public void setJsRef(
     final Permutation permutation, final String slotName, final IJsResourceRef resource) {
   getEntry(permutation.toExternal()).m_slottedJsRef.put(slotName, resource);
 }
 public IJsResourceRef getJsRef(Permutation permutation, final String slotName) {
   return getEntry(permutation.toExternal()).m_slottedJsRef.get(slotName);
 }