func (ushortComponent) PutMat2(b []byte, v [2][2]uint16) {
    binary.LittleEndian.PutUint16(b, v[0][0])
    binary.LittleEndian.PutUint16(b[2:], v[1][0])
    binary.LittleEndian.PutUint16(b[4:], v[0][1])
    binary.LittleEndian.PutUint16(b[6:], v[1][1])