class_docstr: Test COCO utils.
docstr: Test get_label_map for unknown TFDS name.
docstr_tok: ["Test","get_label_map","for","unknown","TFDS","name","."]
code: def test_get_label_map_unknown(self):
      """Test get_label_map for unknown TFDS name."""
      with self.assertRaisesWithPredicateMatch(
          ValueError,
          lambda m: m.args == ("Unsupported TFDS name: unknown",),
      ):
          coco_utils.get_label_map("unknown")
  
imports: from absl.testing import absltest
  from absl.testing import parameterized
  from scenic.dataset_lib.coco_dataset import coco_utils
label_desc: Use image node_id 2 for calling the CocoUtilsTest obj's underlying member method code with example usage: obj.test_get_label_map_unknown() without return types