code: def optional_import(
      module: str,
      version: str = "",
      version_checker: Callable[..., bool] = min_version,
      name: str = "",
      descriptor: str = OPTIONAL_IMPORT_MSG_FMT,
      version_args: Any = None,
      allow_namespace_pkg: bool = False,
      as_type: str = "default",
  ) -> tuple[Any, bool]:
      """
      Imports an optional module specified by `module` string.
      Any importing related exceptions will be stored, and exceptions raise lazily
      when attempting to use the failed-to-import module.
  
      Args:
          module: name of the module to be imported.
          version: version string used by the version_checker.
          version_checker: a callable to check the module version, Defaults to monai.utils.min_version.
          name: a non-module attribute (such as method/class) to import from the imported module.
          descriptor: a format string for the final error message when using a not imported module.
          version_args: additional parameters to the version checker.
          allow_namespace_pkg: whether importing a namespace package is allowed. Defaults to False.
          as_type: there are cases where the optionally imported object is used as
              a base class, or a decorator, the exceptions should raise accordingly. The current supported values
              are "default" (call once to raise), "decorator" (call the constructor and the second call to raise),
              and anything else will return a lazy class that can be used as a base class (call the constructor to raise).
  
      Returns:
          The imported module and a boolean flag indicating whether the import is successful.
  
      Examples::
  
          >>> torch, flag = optional_import('torch', '1.1')
          >>> print(torch, flag)
          <module 'torch' from 'python/lib/python3.6/site-packages/torch/__init__.py'> True
  
          >>> the_module, flag = optional_import('unknown_module')
          >>> print(flag)
          False
          >>> the_module.method  # trying to access a module which is not imported
          OptionalImportError: import unknown_module (No module named 'unknown_module').
  
          >>> torch, flag = optional_import('torch', '42', exact_version)
          >>> torch.nn  # trying to access a module for which there isn't a proper version imported
          OptionalImportError: import torch (requires version '42' by 'exact_version').
  
          >>> conv, flag = optional_import('torch.nn.functional', '1.0', name='conv1d')
          >>> print(conv)
          <built-in method conv1d of type object at 0x11a49eac0>
  
          >>> conv, flag = optional_import('torch.nn.functional', '42', name='conv1d')
          >>> conv()  # trying to use a function from the not successfully imported module (due to unmatched version)
          OptionalImportError: from torch.nn.functional import conv1d (requires version '42' by 'min_version').
      """
  
      tb = None
      exception_str = ""
      if name:
          actual_cmd = f"from {module} import {name}"
      else:
          actual_cmd = f"import {module}"
      try:
          pkg = __import__(module)  # top level module
          the_module = import_module(module)
          if not allow_namespace_pkg:
              is_namespace = getattr(
                  the_module, "__file__", None
              ) is None and hasattr(the_module, "__path__")
              if is_namespace:
                  raise AssertionError
          if (
              name
          ):  # user specified to load class/function/... from the module
              the_module = getattr(the_module, name)
      except (
          Exception
      ) as import_exception:  # any exceptions during import
          tb = import_exception.__traceback__
          exception_str = f"{import_exception}"
      else:  # found the module
          if version_args and version_checker(
              pkg, f"{version}", version_args
          ):
              return the_module, True
          if not version_args and version_checker(pkg, f"{version}"):
              return the_module, True
  
      # preparing lazy error message
      msg = descriptor.format(actual_cmd)
      if version and tb is None:  # a pure version issue
          msg += f" (requires '{module} {version}' by '{version_checker.__name__}')"
      if exception_str:
          msg += f" ({exception_str})"
  
      class _LazyRaise:
          def __init__(self, *_args, **_kwargs):
              _default_msg = (
                  f"{msg}."
                  + "\n\nFor details about installing the optional dependencies, please visit:"
                  + "\n    https://docs.monai.io/en/latest/installation.html#installing-the-recommended-dependencies"
              )
              if tb is None:
                  self._exception = OptionalImportError(_default_msg)
              else:
                  self._exception = OptionalImportError(
                      _default_msg
                  ).with_traceback(tb)
  
          def __getattr__(self, name):
              """
              Raises:
                  OptionalImportError: When you call this method.
              """
              raise self._exception
  
          def __call__(self, *_args, **_kwargs):
              """
              Raises:
                  OptionalImportError: When you call this method.
              """
              raise self._exception
  
          def __getitem__(self, item):
              raise self._exception
  
          def __iter__(self):
              raise self._exception
  
      if as_type == "default":
          return _LazyRaise(), False
  
      class _LazyCls(_LazyRaise):
          def __init__(self, *_args, **kwargs):
              super().__init__()
              if not as_type.startswith("decorator"):
                  raise self._exception
  
      return _LazyCls, False
  
imports: from __future__ import annotations
  import enum
  import functools
  import os
  import pdb
  import re
  import sys
  import warnings
  from collections.abc import Callable, Collection, Hashable, Mapping
  from functools import partial, wraps
  from importlib import import_module
  from pkgutil import walk_packages
  from pydoc import locate
  from re import match
  from types import FunctionType, ModuleType
  from typing import Any, Iterable, cast
  import torch
label_desc: Use image node_id 9 for calling a global function with example usage: optional_import(module, version, version_checker, name, descriptor, version_args, allow_namespace_pkg, as_type) and returns: _LazyCls,  False, _LazyRaise,  False, the_module,  True, the_module,  True