'Compute complex z=x*y, and check that z/x==y and z/y==x.'

def check_div(self, x, y):

    z = (x * y)
    if (x != 0):
        q = (z / x)
        self.assertClose(q, y)
        q = z.__div__(x)
        self.assertClose(q, y)
        q = z.__truediv__(x)
        self.assertClose(q, y)
    if (y != 0):
        q = (z / y)
        self.assertClose(q, x)
        q = z.__div__(y)
        self.assertClose(q, x)
        q = z.__truediv__(y)
        self.assertClose(q, x)
