Create a Json-like dictionary for objects managed by this object
        store.

        Parameters
        ----------
        db_obj : (Sub-class of)ObjectHandle

        Returns
        -------
        (JSON)
            Json-like object, i.e., dictionary.

def to_dict(self, db_obj):
        """Create a Json-like dictionary for objects managed by this object
        store.

        Parameters
        ----------
        db_obj : (Sub-class of)ObjectHandle

        Returns
        -------
        (JSON)
            Json-like object, i.e., dictionary.
        """
        # Base Json serialization for database objects
        return {
            '_id' : db_obj.identifier,
            'timestamp' : str(db_obj.timestamp.isoformat()),
            'properties' : db_obj.properties}