code: def __invert__(self):
      return Quaternion(
          np.array((self.q[0], -self.q[1], -self.q[2], -self.q[3]))
      )
  
imports: import numpy
label_desc: Use image node_id 6 for calling the Quaternion obj's underlying member method code with example usage: obj.__invert__() and returns: Quaternion