text: import numpy as np
  import transformations as trans
  from probreg import l2dist_regs
  from probreg import callbacks
  import utils
  
  source, target = utils.prepare_source_and_target_rigid_3d('bunny.pcd', n_random=0)
  
  cbs = [callbacks.Open3dVisualizerCallback(source, target)]
  tf_param = l2dist_regs.registration_svr(source, target, callbacks=cbs)
  rot = trans.identity_matrix()
  rot[:3, :3] = tf_param.rot
  print("result: ", np.rad2deg(trans.euler_from_matrix(rot)),
        tf_param.scale, tf_param.t)