RestoreWorkItem.
        [Preview API] Restores the deleted work item from Recycle Bin.
        :param :class:`<WorkItemDeleteUpdate> <azure.devops.v5_1.work_item_tracking.models.WorkItemDeleteUpdate>` payload: Paylod with instructions to update the IsDeleted flag to false
        :param int id: ID of the work item to be restored
        :param str project: Project ID or project name
        :rtype: :class:`<WorkItemDelete> <azure.devops.v5_1.work-item-tracking.models.WorkItemDelete>`

def restore_work_item(self, payload, id, project=None):
        """RestoreWorkItem.
        [Preview API] Restores the deleted work item from Recycle Bin.
        :param :class:`<WorkItemDeleteUpdate> <azure.devops.v5_1.work_item_tracking.models.WorkItemDeleteUpdate>` payload: Paylod with instructions to update the IsDeleted flag to false
        :param int id: ID of the work item to be restored
        :param str project: Project ID or project name
        :rtype: :class:`<WorkItemDelete> <azure.devops.v5_1.work-item-tracking.models.WorkItemDelete>`
        """
        route_values = {}
        if project is not None:
            route_values['project'] = self._serialize.url('project', project, 'str')
        if id is not None:
            route_values['id'] = self._serialize.url('id', id, 'int')
        content = self._serialize.body(payload, 'WorkItemDeleteUpdate')
        response = self._send(http_method='PATCH',
                              location_id='b70d8d39-926c-465e-b927-b1bf0e5ca0e0',
                              version='5.1-preview.2',
                              route_values=route_values,
                              content=content)
        return self._deserialize('WorkItemDelete', response)