Error 'unknown MongoDB operation 'aggregate'' when using aggregate in WSo2 Integration Studio?

I am working Wso2 Integration Studio 8.1 version. I want to using aggregate query. But Wso2 Integration Studip giving error as DS Fault Message: Error in MongoQuery.runQuery: DS Fault Message: Unknown MongoDB operation 'aggregate'

I'm afraid it seems the Micro Integrator doesn't support it at the moment. This is from the code which supports the following operations.

private DBConstants.MongoDB.MongoOperation convertToMongoOp(String operation) throws DataServiceFault {
        if (DBConstants.MongoDB.MongoOperationLabels.COUNT.equals(operation)) {
            return DBConstants.MongoDB.MongoOperation.COUNT;
        } else if (DBConstants.MongoDB.MongoOperationLabels.DROP.equals(operation)) {
            return DBConstants.MongoDB.MongoOperation.DROP;
        } else if (DBConstants.MongoDB.MongoOperationLabels.FIND.equals(operation)) {
            return DBConstants.MongoDB.MongoOperation.FIND;
        } else if (DBConstants.MongoDB.MongoOperationLabels.FIND_ONE.equals(operation)) {
            return DBConstants.MongoDB.MongoOperation.FIND_ONE;
        } else if (DBConstants.MongoDB.MongoOperationLabels.INSERT.equals(operation)) {
            return DBConstants.MongoDB.MongoOperation.INSERT;
        } else if (DBConstants.MongoDB.MongoOperationLabels.REMOVE.equals(operation)) {
            return DBConstants.MongoDB.MongoOperation.REMOVE;
        } else if (DBConstants.MongoDB.MongoOperationLabels.UPDATE.equals(operation)) {
            return DBConstants.MongoDB.MongoOperation.UPDATE;
        } else if (DBConstants.MongoDB.MongoOperationLabels.EXISTS.equals(operation)) {
            return DBConstants.MongoDB.MongoOperation.EXISTS;
        }  else if (DBConstants.MongoDB.MongoOperationLabels.CREATE.equals(operation)) {
            return DBConstants.MongoDB.MongoOperation.CREATE;
        } else {
            throw new DataServiceFault("Unknown MongoDB operation '" + operation + "'");
        }
    }

Even the MongoDB connector doesn't support Aggregate operation, hence your best option is to write a Custom mediator to get this done or try to improve the existing connector.