code: def test_variable():
      """Test invoking Variable."""
      value = np.random.rand(5, 4).astype(np.float32)
      layer = layers.Variable(value)
      layer.build([])
      result = layer.call([]).numpy()
      assert np.allclose(result, value)
      assert len(layer.trainable_variables) == 1
  
imports: import deepchem
  import numpy
  import pytest
  import os
label_desc: Use image node_id 5 for calling a global function with example usage: test_variable() without return types