Pauses the current thread for the specified number of seconds

使当前线程暂定 / 睡眠指定时长。

 /**
 * Pauses the current thread for the specified number of seconds.
 *
 * @param seconds The number of seconds to pause.
 */
void sleep(float seconds) {
    long endTime = System.currentTimeMillis() + (long)(seconds*1000);
    while (System.currentTimeMillis() < endTime) {
        synchronized (this) {
            try {
                wait(endTime - System.currentTimeMillis());
            } catch (Exception e) {
            }
        }
    }  
}