这个程序模拟了Go-Back-N协议，在该程序中，窗口限制了发送端最多为5个分组而不需等待确认。多次点击“发送新分组”六次至多次。-This program simulates the Go-Back-N protocol in the program, the window limits the sender group of up to 5 without waiting for confirmation. Repeatedly click the " Send a new group,"　six times to times.