How does `CachedReferenceField` from mongoengine work?

Question

I'm working on a project in which I should use Django, grpc and mongodb. The db operations are readonly except when user interacts with the system for example posting comments or like a post, in that case I need to update the existing db document. I also want to store caches and I do it on retrieve() and list().

Now I have problem with updating caches when user comments for example, I am able to update caches which are made in retrieve() and list() both, but doing it also for nested documents is really hard (it's doable but is not a clean way), hence I want to know if CachedReferenceField comes handy for this purpose or not??

I mean I have my own caching method which is exteremly personal (which I don't like and wish to do it in a "cleaner" way, any help about it would be appreciated too;), doesn't this CachedReferenceField interupt my caching method? or it is internall and has nothing to do with my method of caching?

Here are my models:

import uuid

from django.utils import timezone
from mongoengine import (
    CASCADE,
    BooleanField,
    CachedReferenceField,
    DateTimeField,
    Document,
    EmbeddedDocument,
    EmbeddedDocumentListField,
    IntField,
    ListField,
    StringField,
    UUIDField,
)


### Abstracts
class Base(Document):
    """Provide Base fields which are common among many models."""

    id = IntField(primary_key=True)
    identifier = UUIDField(default=uuid.uuid4, binary=False)
    updated_at = DateTimeField(default=timezone.now)
    created_at = DateTimeField(default=timezone.now)
    image_media_identifier = StringField(max_length=255, unique=True)
    extra_data = StringField()
    title = StringField(max_length=255)

    meta = {"abstract": True}

    def save(self, **kwargs):
        self.updated_at = timezone.now()
        return super().save(**kwargs)


### Embedded models
class Comment(EmbeddedDocument):
    updated_at = DateTimeField(default=timezone.now)
    created_at = DateTimeField(default=timezone.now)
    name = StringField(max_length=255)
    content = StringField()
    visible = BooleanField(default=False)


### Actual Models
class Course(Base):
    description = StringField()
    summary = StringField()
    course_time = IntField()
    price = IntField()
    content = StringField()
    status = StringField(
        choices=[("on_performing", "On_performing"), ("completed", "Completed")],
    )
    lesson_count = IntField()
    likes = IntField(default=0)
    visible = BooleanField(default=True)
    comments = EmbeddedDocumentListField(Comment)

    meta = {
        "collection": "course",
    }


class Lesson(Base):
    lesson_time = IntField()
    video_media_identifier = StringField(max_length=255, unique=True)
    is_active = BooleanField(default=True)
    price = IntField()
    tags = ListField(StringField(max_length=50))
    course = CachedReferenceField(Course, 1, reverse_delete_rule=CASCADE)
    comments = EmbeddedDocumentListField(Comment)

    meta = {
        "collection": "lesson",
    }


class Package(Base):
    is_active = BooleanField(default=True)
    courses = ListField(
        CachedReferenceField(Course, "__all__", reverse_delete_rule=CASCADE)
    )

    meta = {
        "collection": "package",
    }

I read the document but it's not so descriptive.