code: def convert_Concat(
      func, opset_version, input_names, output_names, context
  ):
      if opset_version == 1:
          return (
              onnx_helper.make_node(
                  "Concat", input_names, output_names, axis=func.axis
              ),
          )
      elif opset_version == 4:
          return (
              onnx_helper.make_node(
                  "Concat", input_names, output_names, axis=func.axis
              ),
          )
  
imports: import warnings
  import chainer
  import numpy
  import onnx
  from onnx.mapping import NP_TYPE_TO_TENSOR_TYPE
  from onnx_chainer.functions.opset_version import support
  from onnx_chainer import onnx_helper
label_desc: Use image node_id 2 for calling a global function with example usage: convert_Concat(func, opset_version, input_names, output_names, context) and returns: onnx_helper, onnx_helper