exec method
Implementation
Future<List<RxDocument<RxDocType>>> exec() async {
List<dynamic> result = await collection.database.engine.evaluate(
"process.db['" +
collection.name +
"'].find(" +
jsonEncode(query) +
").exec().then(docs => docs.map(d => d.toJSON(true)));");
var ret = result.map((docData) {
var doc = collection.docCache.getByDocData(docData);
return doc;
}).toList();
return ret;
}