text: 
  import logging
  
  from django.conf import settings
  from django.contrib.auth import SESSION_KEY, get_user_model
  from django.contrib.sessions.models import Session
  from django.utils.timezone import now as timezone_now
  from importlib import import_module
  from typing import List, Mapping, Optional
  
  from zerver.models import Realm, UserProfile, get_user_profile_by_id
  
  session_engine = import_module(settings.SESSION_ENGINE)
  
  def get_session_dict_user(session_dict: Mapping[str, int]) -> Optional[int]:
      # Compare django.contrib.auth._get_user_session_key
      try:
          return get_user_model()._meta.pk.to_python(session_dict[SESSION_KEY])
      except KeyError:
          return None
  
  def get_session_user(session: Session) -> Optional[int]:
      return get_session_dict_user(session.get_decoded())
  
  def user_sessions(user_profile: UserProfile) -> List[Session]:
      return [s for s in Session.objects.all()
              if get_session_user(s) == user_profile.id]
  
  def delete_session(session: Session) -> None:
      session_engine.SessionStore(session.session_key).delete()  # type: ignore # import_module
  
  def delete_user_sessions(user_profile: UserProfile) -> None:
      for session in Session.objects.all():
          if get_session_user(session) == user_profile.id:
              delete_session(session)
  
  def delete_realm_user_sessions(realm: Realm) -> None:
      realm_user_ids = [user_profile.id for user_profile in
                        UserProfile.objects.filter(realm=realm)]
      for session in Session.objects.filter(expire_date__gte=timezone_now()):
          if get_session_user(session) in realm_user_ids:
              delete_session(session)
  
  def delete_all_user_sessions() -> None:
      for session in Session.objects.all():
          delete_session(session)
  
  def delete_all_deactivated_user_sessions() -> None:
      for session in Session.objects.all():
          user_profile_id = get_session_user(session)
          if user_profile_id is None:
              continue
          user_profile = get_user_profile_by_id(user_profile_id)
          if not user_profile.is_active or user_profile.realm.deactivated:
              logging.info("Deactivating session for deactivated user %s" % (user_profile.email,))
              delete_session(session)
  