code: def test_transformer_cfg_registry():
      assert len(transformer_cfg_reg.list_keys()) > 0
  
file_path: gluon-nlp/tests/test_models_transformer.py
imports: import numpy
  import mxnet
  import pytest
  from numpy.testing import assert_allclose
  from gluonnlp.models.transformer import TransformerEncoder, TransformerDecoder, TransformerModel, TransformerInference, transformer_cfg_reg
  from gluonnlp.attention_cell import gen_mem_attn_mask, gen_self_attn_mask
  from gluonnlp.utils.testing import verify_nmt_model, verify_nmt_inference
  from gluonnlp.utils.testing import verify_backbone_fp16
  from gluonnlp.utils.parameter import count_parameters, deduplicate_param_dict
label_desc: Use image node_id 3 for calling a global function with example usage: test_transformer_cfg_registry() without return types