code: def test_dtnn_step():
      n_embedding = 30
      n_distance = 100
      n_hidden = 60
      init = "glorot_uniform"
      activation = "tanh"
  
      layer = dc.models.layers.DTNNStep(
          n_embedding, n_distance, n_hidden, init, activation
      )
      config = layer.get_config()
      layer_copied = dc.models.layers.DTNNStep.from_config(config)
  
      assert layer_copied.n_embedding == layer.n_embedding
      assert layer_copied.n_distance == layer.n_distance
      assert layer_copied.n_hidden == layer.n_hidden
      assert layer_copied.init == layer.init
      assert layer_copied.activation == layer.activation
  
imports: import deepchem
  import pytest
label_desc: Use image node_id 23 for calling a global function with example usage: test_dtnn_step() without return types