code: def inverse_m4x4_transform(mat):
      
      inv_transform = zeros((4, 4))
      rot = mat[:-1, :-1].T
      inv_transform[:-1, :-1] = rot
      inv_transform[:-1, -1] = dot(-rot, mat[:-1, -1])
      inv_transform[-1, -1] = 1
      return inv_transform
docs: Return the inverse transformation of a m4x4 transformation
      :param mat: A m4x4 transform
      :return: inv_transform inverse of the tranformation