Gets the user from current User model using the passed session_key
    :param session_key: django.contrib.sessions.models.Session - session_key
    :return: User instance or None if not found

def get_user_from_session(session_key):
    """
    Gets the user from current User model using the passed session_key
    :param session_key: django.contrib.sessions.models.Session - session_key
    :return: User instance or None if not found
    """
    session = Session.objects.get(session_key=session_key)
    session_data = session.get_decoded()
    uid = session_data.get('_auth_user_id')
    user = get_user_model().objects.filter(id=uid).first()  # get object or none
    return user