code: def test_unknown_labels_not_in_chunks(n_chunks, chunk_size):
      """Checks that unknown labels are not assigned to any chunk."""
      labels = gen_labels_for_chunks(n_chunks, chunk_size)
  
      constraints = Constraints(labels)
      chunks = constraints.chunks(
          n_chunks=n_chunks, chunk_size=chunk_size, random_state=SEED
      )
  
      assert np.all(chunks[labels < 0] < 0)
  
file_path: metric-learn/test/test_constraints.py
imports: import pytest
  import numpy
  from sklearn.utils import shuffle
  from metric_learn.constraints import Constraints
  from sklearn.datasets import make_blobs
label_desc: Use image node_id 4 for calling a global function with example usage: test_unknown_labels_not_in_chunks(n_chunks, chunk_size) without return types