code: def callable_str(*subtypes):
      if subtypes:
          *arg_types, return_type = subtypes
          arg_str = ", ".join(
              _type2str(arg_type) for arg_type in arg_types
          )
          return_type_str = _type2str(return_type)
          return f"Callable[[{arg_str}], {return_type_str}]"
      else:
          return "Callable"
  
file_path: tvm/python/tvm/tir/schedule/_type_checker.py
imports: import collections
  import collections.abc
  import functools
  import inspect
  from typing import Any, Callable, Dict, List, Optional, Tuple, TypeVar, Union
  import typing
label_desc: Use image node_id 4 for calling a global function with example usage: callable_str() and returns: str, arg_str, str, return_type_str, str, str