code: def y_rotate(rotationAmt):
          
          ma4 = Matrix4((math.cos(rotationAmt), 0, math.sin(rotationAmt), 0),
                        (0, 1, 0, 0),
                        (-math.sin(rotationAmt), 0, math.cos(rotationAmt), 0),
                        (0, 0, 0, 1))
          return ma4
docs: Create a matrix that rotates around the y axis.