code: def matrix4x4_to_Rt(extrinsics: Tensor) -> tuple[Tensor, Tensor]:
      r"""Converts 4x4 extrinsics into 3x3 rotation matrix R and 1x3 translation vector ts.
  
      Args:
          extrinsics: pose matrix :math:`(B, 4, 4)`.
  
      Returns:
          R: Rotation matrix, :math:`(B, 3, 3).`
          t: Translation matrix :math:`(B, 3, 1)`.
  
      Example:
          >>> ext = torch.eye(4)[None]
          >>> matrix4x4_to_Rt(ext)
          (tensor([[[1., 0., 0.],
                   [0., 1., 0.],
                   [0., 0., 1.]]]), tensor([[[0.],
                   [0.],
                   [0.]]]))
      """
      KORNIA_CHECK_SHAPE(extrinsics, ["B", "4", "4"])
      R, t = extrinsics[:, :3, :3], extrinsics[:, :3, 3:]
      return R, t
  
imports: from __future__ import annotations
  from typing import Optional
  import torch
  import torch.nn.functional
  from kornia.constants import pi
  from kornia.core import Tensor, concatenate, cos, pad, sin, stack, tensor, where, zeros_like
  from kornia.core.check import KORNIA_CHECK, KORNIA_CHECK_SHAPE
  from kornia.utils import deprecated
  from kornia.utils.helpers import _torch_inverse_cast
label_desc: Use image node_id 38 for calling a global function with example usage: matrix4x4_to_Rt(extrinsics) and returns: R,  t