code: public static long traceEnter(Logger log, String method, Object... args) {
          if (!log.isTraceEnabled()) {
              return 0;
          }
  
          long time = CURRENT_TIME.get();
          log.trace("ENTER {}@{} {}.", method, time, args);
          return time;
      }
docs: Traces the fact that a method entry has occurred.
  
  @param log    The Logger to log to.
  @param method The name of the method.
  @param args   The arguments to the method.
  @return A generated identifier that can be used to correlate this traceEnter with its corresponding traceLeave.
  This is usually generated from the current System time, and when used with traceLeave it can be used to log
  elapsed call times.