code: def test_concatenate():
      model = nn.HybridConcatenate(axis=1)
      model.add(nn.Dense(128, activation="tanh", in_units=10))
      model.add(nn.Dense(64, activation="tanh", in_units=10))
      model.add(nn.Dense(32, in_units=10))
      model2 = nn.Concatenate(axis=1)
      model2.add(nn.Dense(128, activation="tanh", in_units=10))
      model2.add(nn.Dense(64, activation="tanh", in_units=10))
      model2.add(nn.Dense(32, in_units=10))
  
      # ndarray
      model.initialize(mx.init.Xavier(magnitude=2.24))
      model2.initialize(mx.init.Xavier(magnitude=2.24))
      x = model(mx.np.zeros((32, 10)))
      x2 = model2(mx.np.zeros((32, 10)))
      assert x.shape == (32, 224)
      assert x2.shape == (32, 224)
      x.wait_to_read()
      x2.wait_to_read()
  
imports: from __future__ import absolute_import
  from __future__ import division
  import os
  from uuid import uuid4
  import numpy
  import mxnet
  from mxnet import gluon, autograd, np, npx
  from mxnet.test_utils import use_np, assert_almost_equal, check_gluon_hybridize_consistency, assert_allclose
  from mxnet.gluon import nn
  from mxnet.base import MXNetError
  import random
  import pytest
label_desc: Use image node_id 21 for calling a global function with example usage: test_concatenate() without return types