code: def test_locally_linear_embedding(get_mats):
      """Test locally_linear_embedding helper function."""
      n_matrices, n_channels, n_comps, n_neighbors = 4, 3, 2, 2
      covmats = get_mats(n_matrices, n_channels, "spd")
      embedding, error = locally_linear_embedding(
          covmats, n_neighbors=n_neighbors, n_components=n_comps
      )
      assert embedding.shape == (n_matrices, n_comps)
      assert isinstance(error, float)
  
imports: from conftest import get_metrics
  import numpy
  from sklearn.neighbors import NearestCentroid
  from pyriemann.datasets import make_gaussian_blobs
  from pyriemann.embedding import SpectralEmbedding, LocallyLinearEmbedding, barycenter_weights, locally_linear_embedding
  import pytest
label_desc: Use image node_id 5 for calling a global function with example usage: test_locally_linear_embedding(get_mats) without return types