Error when using pool=true on connection string.

[deleteman]

Hello, using the "pool=true" on the connection url, I get the following error when querying:

TypeError: undefined is not a function
    at Driver.close (C:\Users\fernando.doglio\Documents\Trabajo\Thomas Cook\tc-retailv2-api\node_modules\orm\lib\Drivers\DML\mysql.js:72:10)
    at ORM.close (C:\Users\fernando.doglio\Documents\Trabajo\Thomas Cook\tc-retailv2-api\node_modules\orm\lib\ORM.js:212:14)
    at C:\Users\fernando.doglio\Documents\Trabajo\Thomas Cook\tc-retailv2-api\src\services\datastore\mysql\models\assetDetail.js:16:10
    at C:\Users\fernando.doglio\Documents\Trabajo\Thomas Cook\tc-retailv2-api\src\services\datastore\mysql\models\dbModel.js:22:3
    at C:\Users\fernando.doglio\Documents\Trabajo\Thomas Cook\tc-retailv2-api\node_modules\orm\lib\Model.js:321:11
    at Query._callback (C:\Users\fernando.doglio\Documents\Trabajo\Thomas Cook\tc-retailv2-api\node_modules\orm\lib\Drivers\DML\mysql.js:218:11)
    at Query.Sequence.end (C:\Users\fernando.doglio\Documents\Trabajo\Thomas Cook\tc-retailv2-api\node_modules\mysql\lib\protocol\sequences\Sequence.js:66:24)
    at Query._handleFinalResultPacket (C:\Users\fernando.doglio\Documents\Trabajo\Thomas Cook\tc-retailv2-api\node_modules\mysql\lib\protocol\sequences\Query.js:139:8)
    at Query.EofPacket (C:\Users\fernando.doglio\Documents\Trabajo\Thomas Cook\tc-retailv2-api\node_modules\mysql\lib\protocol\sequences\Query.js:123:8)
    at Protocol._parsePacket (C:\Users\fernando.doglio\Documents\Trabajo\Thomas Cook\tc-retailv2-api\node_modules\mysql\lib\protocol\Protocol.js:169:24)

Is there anything special I should be doing if I use a pool? The documentation doesn't say much.. for what I could gather, it's failing because I'm not passing a callback for the "close" method, but what should I be passing? Why do I need a callback in this case?