def _whichmodule(obj, name):
    """Find the module an object belongs to.

    This function differs from ``pickle.whichmodule`` in two ways:
    - it does not mangle the cases where obj's module is __main__ and obj was
      not found in any module.
    - Errors arising during module introspection are ignored, as those errors
      are considered unwanted side effects.
    """
    module_name = getattr(obj, "__module__", None)

    if module_name is not None:
        return module_name
    # Protect the iteration by using a copy of sys.modules against dynamic
    # modules that trigger imports of other modules upon calls to getattr or
    # other threads importing at the same time.
    for module_name, module in sys.modules.copy().items():
        # Some modules such as coverage can inject non-module objects inside
        # sys.modules
        if (
            module_name == "__main__"
            or module is None
            or not isinstance(module, types.ModuleType)
        ):
            continue
        try:
            if _getattribute(module, name)[0] is obj:
                return module_name
        except Exception:
            pass
    return None
Find the module an object belongs to.

    This function differs from ``pickle.whichmodule`` in two ways:
    - it does not mangle the cases where obj's module is __main__ and obj was
      not found in any module.
    - Errors arising during module introspection are ignored, as those errors
      are considered unwanted side effects.
    
numba/cloudpickle/cloudpickle.py