How to use the workflows.models.StateObjectRelation.objects.get function in workflows

def remove_workflow(self):
        """ Remove entirely a worflow for an instance. """

        ctype = ContentType.objects.get_for_model(self)
        try:
            workflow = self.state.workflow
            wor = workflows.models.WorkflowObjectRelation.objects.get(
                content_type=ctype, content_id=self.pk
            )
            sor = workflows.models.StateObjectRelation.objects.get(
                content_type=ctype, content_id=self.pk
            )
        except workflows.models.WorkflowObjectRelation.DoesNotExist:
            pass
        except workflows.models.StateObjectRelation.DoesNotExist:
            pass

        with transaction.atomic():
            wor.delete()
            sor.delete()

def set_state(obj, state):
    """Sets the state for the passed object to the passed state and updates
    the permissions for the object.

    **Parameters:**

    obj
        The object for which the workflow state should be set. Can be any
        Django model instance.

    state
        The state which should be set to the passed object.
    """
    ctype = ContentType.objects.get_for_model(obj)
    try:
        sor = StateObjectRelation.objects.get(content_type=ctype, content_id=obj.id)
    except StateObjectRelation.DoesNotExist:
        sor = StateObjectRelation.objects.create(content=obj, state=state)
    else:
        sor.state = state
        sor.save()
    update_permissions(obj)

def get_state(obj):
    """Returns the current workflow state for the passed object.

    **Parameters:**

    obj
        The object for which the workflow state should be returned. Can be any
        Django model instance.
    """
    ctype = ContentType.objects.get_for_model(obj)
    try:
        sor = StateObjectRelation.objects.get(content_type=ctype, content_id=obj.id)
    except StateObjectRelation.DoesNotExist:
        return None
    else:
        return sor.state

ctype
        The content type from which the passed workflow should be removed.
        Must be a ContentType instance.
    """
    # First delete all states, inheritance blocks and permissions from ctype's
    # instances which have passed workflow.
    workflow = get_workflow_for_model(ctype)
    for obj in get_objects_for_workflow(workflow):
        # Only take care of the given ctype.
        obj_ctype = ContentType.objects.get_for_model(obj)
        if ctype != obj_ctype:
            continue
        try:
            ctype = ContentType.objects.get_for_model(obj)
            sor = StateObjectRelation.objects.get(content_id=obj.id, content_type=ctype)
        except StateObjectRelation.DoesNotExist:
            pass
        else:
            sor.delete()

        # Reset all permissions
        permissions.utils.reset(obj)

    try:
        wmr = WorkflowModelRelation.objects.get(content_type=ctype)
    except WorkflowModelRelation.DoesNotExist:
        pass
    else:
        wmr.delete()