How to use the blinker._saferef.BoundMethodWeakref function in blinker

def callable_reference(object, callback=None):
    """Return an annotated weak ref, supporting bound instance methods."""
    if hasattr(object, 'im_self') and object.im_self is not None:
        return BoundMethodWeakref(target=object, on_delete=callback)
    elif hasattr(object, '__self__') and object.__self__ is not None:
        return BoundMethodWeakref(target=object, on_delete=callback)
    return annotatable_weakref(object, callback)

except NameError:
    text = str


def hashable_identity(obj):
    if hasattr(obj, '__func__'):
        return (id(obj.__func__), id(obj.__self__))
    elif hasattr(obj, 'im_func'):
        return (id(obj.im_func), id(obj.im_self))
    elif isinstance(obj, text):
        return obj
    else:
        return id(obj)


WeakTypes = (ref, BoundMethodWeakref)


class annotatable_weakref(ref):
    """A weakref.ref that supports custom instance attributes."""


def reference(object, callback=None, **annotations):
    """Return an annotated weak ref."""
    if callable(object):
        weak = callable_reference(object, callback)
    else:
        weak = annotatable_weakref(object, callback)
    for key, value in annotations.items():
        setattr(weak, key, value)
    return weak

def callable_reference(object, callback=None):
    """Return an annotated weak ref, supporting bound instance methods."""
    if hasattr(object, 'im_self') and object.__self__ is not None:
        return BoundMethodWeakref(target=object, on_delete=callback)
    elif hasattr(object, '__self__') and object.__self__ is not None:
        return BoundMethodWeakref(target=object, on_delete=callback)
    return annotatable_weakref(object, callback)

except NameError:
    text = str


def hashable_identity(obj):
    if hasattr(obj, '__func__'):
        return (id(obj.__func__), id(obj.__self__))
    elif hasattr(obj, 'im_func'):
        return (id(obj.im_func), id(obj.im_self))
    elif isinstance(obj, text):
        return obj
    else:
        return id(obj)


WeakTypes = (ref, BoundMethodWeakref)


class annotatable_weakref(ref):
    """A weakref.ref that supports custom instance attributes."""


def reference(object, callback=None, **annotations):
    """Return an annotated weak ref."""
    if callable(object):
        weak = callable_reference(object, callback)
    else:
        weak = annotatable_weakref(object, callback)
    for key, value in annotations.items():
        setattr(weak, key, value)
    return weak

def callable_reference(object, callback=None):
    """Return an annotated weak ref, supporting bound instance methods."""
    if hasattr(object, 'im_self') and object.im_self is not None:
        return BoundMethodWeakref(target=object, on_delete=callback)
    elif hasattr(object, '__self__') and object.__self__ is not None:
        return BoundMethodWeakref(target=object, on_delete=callback)
    return annotatable_weakref(object, callback)

def __new__(cls, name):
        try:
            return cls.symbols[name]
        except KeyError:
            return cls.symbols.setdefault(name, _symbol(name))


def hashable_identity(obj):
    if hasattr(obj, 'im_func'):
        return (id(obj.__func__), id(obj.__self__))
    else:
        return id(obj)


WeakTypes = (ref, BoundMethodWeakref)


class annotatable_weakref(ref):
    """A weakref.ref that supports custom instance attributes."""


def reference(object, callback=None, **annotations):
    """Return an annotated weak ref."""
    if isinstance(object, collections.Callable):
        weak = callable_reference(object, callback)
    else:
        weak = annotatable_weakref(object, callback)
    for key, value in list(annotations.items()):
        setattr(weak, key, value)
    return weak

"""
    try:
        im_self = get_self(target)
    except AttributeError:
        if callable(on_delete):
            return weakref.ref(target, on_delete)
        else:
            return weakref.ref(target)
    else:
        if im_self is not None:
            # Turn a bound method into a BoundMethodWeakref instance.
            # Keep track of these instances for lookup by disconnect().
            assert hasattr(target, 'im_func') or hasattr(target, '__func__'), (
                "safe_ref target %r has im_self, but no im_func, "
                "don't know how to create reference" % target)
            reference = BoundMethodWeakref(target=target, on_delete=on_delete)
            return reference

def callable_reference(object, callback=None):
    """Return an annotated weak ref, supporting bound instance methods."""
    if hasattr(object, 'im_self') and object.im_self is not None:
        return BoundMethodWeakref(target=object, on_delete=callback)
    elif hasattr(object, '__self__') and object.__self__ is not None:
        return BoundMethodWeakref(target=object, on_delete=callback)
    return annotatable_weakref(object, callback)

def callable_reference(object, callback=None):
    """Return an annotated weak ref, supporting bound instance methods."""
    if hasattr(object, 'im_self') and object.im_self is not None:
        return BoundMethodWeakref(target=object, on_delete=callback)
    elif hasattr(object, '__self__') and object.__self__ is not None:
        return BoundMethodWeakref(target=object, on_delete=callback)
    return annotatable_weakref(object, callback)

except NameError:
    text = str


def hashable_identity(obj):
    if hasattr(obj, '__func__'):
        return (id(obj.__func__), id(obj.__self__))
    elif hasattr(obj, 'im_func'):
        return (id(obj.im_func), id(obj.im_self))
    elif isinstance(obj, text):
        return obj
    else:
        return id(obj)


WeakTypes = (ref, BoundMethodWeakref)


class annotatable_weakref(ref):
    """A weakref.ref that supports custom instance attributes."""


def reference(object, callback=None, **annotations):
    """Return an annotated weak ref."""
    if callable(object):
        weak = callable_reference(object, callback)
    else:
        weak = annotatable_weakref(object, callback)
    for key, value in annotations.items():
        setattr(weak, key, value)
    return weak