old_contents: var config = require('../../config');
  var knex = require('knex')({
    debug : process.env.DEBUG,
    client : config('/dbAdapter') === 'postgres' ? 'pg' : config('/dbAdapter'),
    connection : config('/dbConnection')
  });
  
  module.exports = () => knex;
  module.exports['@singleton'] = true;
  
new_contents: var config = require('../../config');
  var knex = require('knex')({
    debug : process.env.DEBUG,
    client : config('/dbAdapter'),
    connection : config('/dbConnection')
  });
  
  module.exports = () => knex;
  module.exports['@singleton'] = true;
  
subject: Simplify knex.js