ix. In a sequence diagram, when one object's method calls the method of another, an arrow is drawn between the lines of both objects x. To combine separate shapes into a drawable object whose parts move together, the Layer class is used. ii. (30) A quaternion is a kind of number which describes how physical objects spin. It combines 4 real number values, real, i.val, jval and k.val. If these values are a, b, c, and d, respectively, the quaternion is written as a + b + cJ + dk. Write the functions--init--(self, r, i-val, j-val , k val) and ~_str..(self) for the Python Quaternion class