code: def test_luv2yuv():
      cv_luv = cv.cvtColor(cv_bgr, cv.COLOR_BGR2LUV)
      cv_luv = caer.to_tensor(cv_luv, cspace="luv")
  
      yuv = caer.luv2yuv(cv_luv)
  
      assert len(yuv.shape) == 3
      assert isinstance(yuv, caer.Tensor)
      assert yuv.is_yuv()
  
file_path: caer/tests/color/test_luv.py
imports: import caer
  import cv2
  import os
label_desc: Use image node_id 7 for calling a global function with example usage: test_luv2yuv() without return types