code: public void enterScopeNonInheritable() {
  		checkState(nonInheritableScopeCache.get() == null, "Scope has already been entered. Forgot to call exitScope()?");
  		Map<Key<?>, Object> scopeMap = newHashMap();
  		nonInheritableScopeCache.set(scopeMap);
  		log.debug("Entered non-inheritable scope.");
  	}
docs: Enters a new scope context for the current thread (without subthreads) setting a scope map
  to the internal {@link ThreadLocal}.
  
  @throws IllegalStateException
  if there is already a scope context for the current thread