code: function Pool(config) {
  	if(!(this instanceof Pool)) {
  		return new Pool(config);
  	}
  	var self = this;
  	if(!config) { throw new TypeError("config not set"); }
  	self._pool = require('mysql').createPool(config);
  	self._get_connection = Q.nfbind(self._pool.getConnection.bind(self._pool));
  	db.Pool.call(this);
  }
docs: Create MySQL connection pool object