docstr: Tests face line parsing.
code: def test_parse_face(self):
      """Tests face line parsing."""
      face_data = [3, 10, 20, 30]
      parsed_face = demo_utils._parse_face(
          " ".join(map(str, face_data))
      )
      self.assertListEqual(parsed_face, face_data[1:])
  
file_path: tensorboard/tensorboard/plugins/mesh/demo_utils_test.py
imports: import os
  import tensorflow
  from tensorboard.plugins.mesh import demo_utils
label_desc: Use image node_id 3 for calling the TestPLYReader obj's underlying member method code with example usage: obj.test_parse_face() without return types