func (o *NAWS) writeSizeSubnegotiation(width, height int) {
o.Terminal().Keyboard().WriteCommand(telnet.Command{
OpCode: telnet.SB,
Option: naws,
Subnegotiation: []byte{
byte((width >> 8) & 0xff),
byte(width & 0xff),
byte((height >> 8) & 0xff),
byte(height & 0xff),
},
}, nil)
}