code: def create_from_axis_angle(cls, angle, ax, ay, az, degrees=False):
          
          if degrees:
              angle = np.radians(angle)
          while angle < 0:
              angle += np.pi*2
          angle2 = angle/2.0
          sinang2 = np.sin(angle2)
          return Quaternion(np.cos(angle2), ax*sinang2, ay*sinang2, az*sinang2)
docs: Classmethod to create a quaternion from an axis-angle representation. 
          (angle should be in radians).