static _findDatabaseRows(lookupObj) {
        const querySpec = {
            table: this.modelName,
        };
        if (lookupObj) {
            querySpec.clauses = [
                {
                    type: FILTER,
                    payload: lookupObj,
                },
            ];
        }
        return this.session.query(querySpec).rows;
    }
Finds all rows in this model's table that match the given `lookupObj`.
If no `lookupObj` is passed, all rows in the model's table will be returned.

@param  {*}  props - a key-value that {@link Model} instances should have to be considered as existing.
@return {Boolean} a boolean indicating if entity with `props` exists in the state
@private