code: def test_electrodeselection(get_mats, get_labels):
      """Test transform of channelselection."""
      n_matrices, n_channels, n_classes = 10, 30, 2
      covmats = get_mats(n_matrices, n_channels, "spd")
      labels = get_labels(n_matrices, n_classes)
      se = ElectrodeSelection()
      se.fit(covmats, labels)
      se.transform(covmats)
  
imports: from numpy.testing import assert_array_equal
  from pyriemann.channelselection import ElectrodeSelection, FlatChannelRemover
label_desc: Use image node_id 1 for calling a global function with example usage: test_electrodeselection(get_mats, get_labels) without return types