code: def test_dropout_layer(self):
      test_input = np.ones((50, 20))
      dropout_layer = layers.Dropout(proba=0.5)
  
      y = dropout_layer.output(test_input, training=True)
      layer_output = self.eval(y)
  
      self.assertGreater(layer_output.sum(), 900)
      self.assertLess(layer_output.sum(), 1100)
  
      self.assertTrue(
          np.all(np.bitwise_or(layer_output == 0, layer_output == 2))
      )
  
imports: from scipy import stats
  import numpy
  from neupy import layers
  from neupy.exceptions import LayerConnectionError
  from base import BaseTestCase
label_desc: Use image node_id 1 for calling the DropoutLayerTestCase obj's underlying member method code with example usage: obj.test_dropout_layer() without return types