code: def test_rgb2hls():
      cv_rgb = cv.cvtColor(cv_bgr, cv.COLOR_BGR2RGB)
      cv_rgb = caer.to_tensor(cv_rgb, cspace="rgb")
      hls = caer.rgb2hls(cv_rgb)
  
      assert len(hls.shape) == 3
      assert isinstance(hls, caer.Tensor)
      assert hls.is_hls()
  
file_path: caer/tests/color/test_rgb.py
imports: import caer
  import cv2
  import os
label_desc: Use image node_id 4 for calling a global function with example usage: test_rgb2hls() without return types