/**
     * Returns the approximate accumulated elapsed time (in milliseconds)
     * that the thread associated with this <tt>ThreadInfo</tt>
     * has waited for notification
     * since thread contention monitoring is enabled.
     * I.e. the total accumulated time the thread has been in the
     * {@link java.lang.Thread.State#WAITING WAITING}
     * or {@link java.lang.Thread.State#TIMED_WAITING TIMED_WAITING} state
     * since thread contention monitoring is enabled.
     * This method returns <tt>-1</tt> if thread contention monitoring
     * is disabled.
     *
     * <p>The Java virtual machine may measure the time with a high
     * resolution timer.  This statistic is reset when
     * the thread contention monitoring is reenabled.
     *
     * @return the approximate accumulated elapsed time in milliseconds
     * that a thread has been in the <tt>WAITING</tt> or
     * <tt>TIMED_WAITING</tt> state;
     * <tt>-1</tt> if thread contention monitoring is disabled.
     *
     * @throws java.lang.UnsupportedOperationException if the Java
     * virtual machine does not support this operation.
     *
     * @see ThreadMXBean#isThreadContentionMonitoringSupported
     * @see ThreadMXBean#setThreadContentionMonitoringEnabled
     */

    public long getWaitedTime() {

  {- -------------------------------------------
  (1) waitedTime フィールドの値をリターンするだけ.
      ---------------------------------------- -}

            return waitedTime;
        }