code: def parse_nni_function(code):
      
      name, call = parse_annotation_function(code, 'function_choice')
      funcs = [ast.dump(func, False) for func in call.args]
      convert_args_to_dict(call, with_lambda=True)
  
      name_str = astor.to_source(name).strip()
      call.keywords[0].value = ast.Str(s=name_str)
  
      return call, funcs
docs: Parse `nni.function_choice` expression.
      Return the AST node of annotated expression and a list of dumped function call expressions.
      code: annotation string