DB Connection close issue in Node.js using trireme-jdbc

Question

I have developed and deployed a Node.js application in apigee edge, which performs few CRUD operations. To establish db connection I have used trireme-jdbc module of node.js. I am able to perform all CRUD operations well through trireme-jdbc but I have problem with DB session close using db.close() function in trireme-jdbc. When I use db.close() it do not close currently active/open session from the pool. I want to know is there any other process or way to close db connection perfectly. Also I want to close all active connections from pool.

Any help will be appreciated. Below is the sample code to establish connection, run a select query and used db.close() to close session. My database is Openedge/Progress.

var jdbc = require('trireme-jdbc');

var db = new jdbc.Database({
         url : connectionURL, 
         properties: {
               user: 'XXXXXX',
           password: 'XXXXXX',
         },
         minConnections:1,
         maxConnections:2,
         idleTimeout:10
         });

db.execute('select * from users ', function(err, result, rows) {
          console.log(err);
          console.log(result);
          rows.forEach(function(row) {
          console.log(row);
});

db.close();   // Used to close DB session/connection.
});