socket.address()
返回包含套接字地址信息的对象。对于 UDP 套接字，此对象将包含 address、family 和 port 属性。
¥Returns an object containing the address information for a socket.
For UDP sockets, this object will contain address, family, and port
properties.
如果在未绑定的套接字上调用此方法将抛出 EBADF。
¥This method throws EBADF if called on an unbound socket.