How to use the rope.base.taskhandle.NullTaskHandle function in rope

def _change_calls(self, call_changer, in_hierarchy=None, resources=None,
                      handle=taskhandle.NullTaskHandle()):
        if resources is None:
            resources = self.project.get_python_files()
        changes = ChangeSet('Changing signature of <%s>' % self.name)
        job_set = handle.create_jobset('Collecting Changes', len(resources))
        finder = occurrences.create_finder(
            self.project, self.name, self.pyname, instance=self.primary,
            in_hierarchy=in_hierarchy and self.is_method())
        if self.others:
            name, pyname = self.others
            constructor_finder = occurrences.create_finder(
                self.project, name, pyname, only_calls=True)
            finder = _MultipleFinders([finder, constructor_finder])
        for file in resources:
            job_set.started_job(file.path)
            change_calls = _ChangeCallsInModule(
                self.project, finder, file, call_changer)

    def do(self, changes, task_handle=taskhandle.NullTaskHandle()):
        """Perform the change and add it to the `self.undo_list`

        Note that uninteresting changes (changes to ignored files)
        will not be appended to `self.undo_list`.

        """
        try:
            self.current_change = changes
            changes.do(change.create_job_set(task_handle, changes))
        finally:
            self.current_change = None
        if self._is_change_interesting(changes):
            self.undo_list.append(changes)
            self._remove_extra_items()
        del self.redo_list[:]

    def get_classes(self, task_handle=taskhandle.NullTaskHandle()):
        warnings.warn('`PyCore.get_classes()` is deprecated',
                      DeprecationWarning, stacklevel=2)
        return []

def _change_calls(self, call_changer, in_hierarchy=None, resources=None,
                      handle=taskhandle.NullTaskHandle()):
        if resources is None:
            resources = self.project.get_python_files()
        changes = ChangeSet('Changing signature of <%s>' % self.name)
        job_set = handle.create_jobset('Collecting Changes', len(resources))
        finder = occurrences.create_finder(
            self.project, self.name, self.pyname, instance=self.primary,
            in_hierarchy=in_hierarchy and self.is_method())
        if self.others:
            name, pyname = self.others
            constructor_finder = occurrences.create_finder(
                self.project, name, pyname, only_calls=True)
            finder = _MultipleFinders([finder, constructor_finder])
        for file in resources:
            job_set.started_job(file.path)
            change_calls = _ChangeCallsInModule(
                self.project, finder, file, call_changer)

def find_occurrences(project, resource, offset, unsure=False, resources=None,
                     in_hierarchy=False,
                     task_handle=taskhandle.NullTaskHandle()):
    """Return a list of `Location`\s

    If `unsure` is `True`, possible matches are returned, too.  You
    can use `Location.unsure` to see which are unsure occurrences.
    `resources` can be a list of `rope.base.resource.File`\s that
    should be searched for occurrences; if `None` all python files
    in the project are searched.

    """
    name = worder.get_name_at(resource, offset)
    this_pymodule = project.get_pymodule(resource)
    primary, pyname = rope.base.evaluate.eval_location2(
        this_pymodule, offset)

    def is_match(occurrence):
        return unsure

def _change_calls(self, call_changer, in_hierarchy=None, resources=None,
                      handle=taskhandle.NullTaskHandle()):
        if resources is None:
            resources = self.pycore.get_python_files()
        changes = ChangeSet('Changing signature of <%s>' % self.name)
        job_set = handle.create_jobset('Collecting Changes', len(resources))
        finder = occurrences.create_finder(
            self.pycore, self.name, self.pyname, instance=self.primary,
            in_hierarchy=in_hierarchy and self.is_method())
        if self.others:
            name, pyname = self.others
            constructor_finder = occurrences.create_finder(
                self.pycore, name, pyname, only_calls=True)
            finder = _MultipleFinders([finder, constructor_finder])
        for file in resources:
            job_set.started_job(file.path)
            change_calls = _ChangeCallsInModule(
                self.pycore, finder, file, call_changer)

def get_changes(self, remove=True, only_current=False, resources=None,
                    docs=False, task_handle=taskhandle.NullTaskHandle()):
        if resources is None:
            if rename._is_local(self.pyname):
                resources = [self.resource]
            else:
                resources = self.project.get_python_files()
        if only_current:
            resources = [self.original]
            if remove and self.original != self.resource:
                resources.append(self.resource)
        changes = ChangeSet('Inline variable <%s>' % self.name)
        jobset = task_handle.create_jobset('Calculating changes',
                                           len(resources))

        for resource in resources:
            jobset.started_job(resource.path)
            if resource == self.resource:

def get_changes(self, getter=None, setter=None, resources=None,
                    task_handle=taskhandle.NullTaskHandle()):
        """Get the changes this refactoring makes

        If `getter` is not `None`, that will be the name of the
        getter, otherwise ``get_${field_name}`` will be used.  The
        same is true for `setter` and if it is None set_${field_name} is
        used.

        `resources` can be a list of `rope.base.resource.File`\s that
        the refactoring should be applied on; if `None` all python
        files in the project are searched.

        """
        if resources is None:
            resources = self.project.get_python_files()
        changes = ChangeSet('Encapsulate field <%s>' % self.name)
        job_set = task_handle.create_jobset('Collecting Changes',

def get_changes(self, remove=True, only_current=False, resources=None,
                    docs=False, task_handle=taskhandle.NullTaskHandle()):
        if resources is None:
            if rename._is_local(self.pyname):
                resources = [self.resource]
            else:
                resources = self.project.get_python_files()
        if only_current:
            resources = [self.original]
            if remove and self.original != self.resource:
                resources.append(self.resource)
        changes = ChangeSet('Inline variable <%s>' % self.name)
        jobset = task_handle.create_jobset('Calculating changes',
                                           len(resources))

        for resource in resources:
            jobset.started_job(resource.path)
            if resource == self.resource:

    def get_classes(self, task_handle=taskhandle.NullTaskHandle()):
        warnings.warn('`PyCore.get_classes()` is deprecated',
                      DeprecationWarning, stacklevel=2)
        return []