@NotNull
   private static List<BsonDocument> getAggregation (String queryAggregation) {
      // parse the aggregation query string into a List of BsonDocument
      return new BsonArrayCodec().decode(new JsonReader(queryAggregation), DecoderContext.builder().build())
          .stream().map(BsonValue::asDocument)
          .collect(Collectors.toList());
   }
Constructs the SqlManager.

@param opts the ReplicaDB ToolOptions describing the user's requested action.
src/main/java/org/replicadb/manager/MongoDBManager.java