@Override
    public Map<String, String> getCopyOfContextMap() {
        Map<String, String> oldMap = inheritableThreadLocal.get();
        if (oldMap != null) {
            return new HashMap<>(oldMap);
        } else {
            return null;
        }
    }
@ Override public Map < String , String > getCopyOfContextMap ( ) { Map < String , String > oldMap = inheritableThreadLocal . get ( ) ; if ( oldMap != null ) { return new HashMap < > ( oldMap ) ; } else { return null ; } }
Return a copy of the current thread's context map.
Returned value may be null.