code: private static StackTraceElement[] getRealStackTrack(StackTraceElement[] stackTrace,
                                                         String stackTraceOrigin) {
      int ignoreDepth = 0;
      int allDepth = stackTrace.length;
      String className;
      for (int i = allDepth - 1; i >= 0; i--) {
        className = stackTrace[i].getClassName();
        if (className.startsWith(XLOG_STACK_TRACE_ORIGIN)
            || (stackTraceOrigin != null && className.startsWith(stackTraceOrigin))) {
          ignoreDepth = i + 1;
          break;
        }
      }
      int realDepth = allDepth - ignoreDepth;
      StackTraceElement[] realStack = new StackTraceElement[realDepth];
      System.arraycopy(stackTrace, ignoreDepth, realStack, 0, realDepth);
      return realStack;
    }
docs: Get the real stack trace, all elements that come from XLog library would be dropped.
  
  @param stackTrace the full stack trace
  @return the real stack trace, all elements come from system and library user