code: def _get_converters():
      global _converters
  
      if _converters is not None:
          return _converters
  
      _converters = {
          name: FunctionConverter(
              getattr(functions, "convert_" + name, None)
          )
          for name in _supported_function_node_set
      }
      return _converters
  
imports: from contextlib import contextmanager
  import chainer.functions
  from onnx_chainer import functions
  from onnx_chainer.functions.converter import FunctionConverter
  from onnx_chainer.replace_func import fake_as_funcnode
label_desc: Use image node_id 1 for calling a global function with example usage: _get_converters() and returns: _converters, _converters