code: public static void parseTraceKey(Map<String, String> tracerMap, String key, String value) {
          String lowKey = key.substring(PREFIX.length());
          String realKey = TRACER_KEY_MAP.get(lowKey);
          tracerMap.put(realKey == null ? lowKey : realKey, value);
      }
docs: Parse tracer key
  
  @param tracerMap tracer map
  @param key       tracer key
  @param value     tracer value