FocusSquare binary issue?

[Parameshvadivel]

Binary operator '+=' cannot be applied to two 'SCNVector3' operands

  ```

s1.position += SCNVector3Make(-(sl / 2 - c), -(sl - c), 0)
s2.position += SCNVector3Make(sl / 2 - c, -(sl - c), 0)
s3.position += SCNVector3Make(-sl, -sl / 2, 0)
s4.position += SCNVector3Make(sl, -sl / 2, 0)
s5.position += SCNVector3Make(-sl, sl / 2, 0)
s6.position += SCNVector3Make(sl, sl / 2, 0)
s7.position += SCNVector3Make(-(sl / 2 - c), sl - c, 0)
s8.position += SCNVector3Make(sl / 2 - c, sl - c, 0)