return stackTrace[index];
return index < stackTrace.length ? stackTrace[index] : null;
  private StackTraceElement getCallerStackFrame()  {    Throwable t = new Throwable();    StackTraceElement[] stackTrace = t.getStackTrace();    int index = 0;    // skip to stackentries until this class    while(!stackTrace[index].getClassName().equals(getClass().getName())){index++;}    // skip the stackentries of this class    while(stackTrace[index].getClassName().equals(getClass().getName())){index++;}    return stackTrace[index];  }