How to use the loopback-connector.SqlConnector function in loopback-connector

// LoopBack uses GeoPoint instead.
  // The Point type can be removed at some point in the future.
  defineType(function Point() {
  });
}

/**
 * @constructor
 * Constructor for MySQL connector
 * @param {Object} client The node-mysql client object
 */
function MySQL(settings) {
  SqlConnector.call(this, 'mysql', settings);
}

require('util').inherits(MySQL, SqlConnector);

MySQL.prototype.connect = function(callback) {
  var self = this;
  var options = generateOptions(this.settings);
  var s = self.settings || {};

  if (this.client) {
    if (callback) {
      process.nextTick(function() {
        callback(null, self.client);
      });
    }
  } else {
    this.client = mysql.createPool(options);
    this.client.getConnection(function(err, connection) {
      var conn = connection;

* @prop {String} database The database name (TNS listener name)
 * @prop {Boolean|Number} debug If true, print debug messages. If Number, ?
 * @class
 */
function Oracle(oracle, settings) {
  this.constructor.super_.call(this, 'oracle', settings);
  this.driver = oracle;
  this.pool = null;
  this.parallelLimit = settings.maxConn || settings.poolMax || 16;
  if (settings.debug || debug.enabled) {
    debug('Settings: %j', settings);
  }
}

// Inherit from loopback-datasource-juggler BaseSQL
require('util').inherits(Oracle, SqlConnector);

Oracle.prototype.debug = function() {
  if (this.settings.debug || debug.enabled) {
    debug.apply(null, arguments);
  }
};

/**
 * Connect to Oracle
 * @param {Function} [callback] The callback after the connection is established
 */
Oracle.prototype.connect = function(callback) {
  var self = this;
  if (this.pool) {
    if (callback) {
      process.nextTick(function() {

}

/**
 * @constructor
 * Constructor for Cassandra connector
 * @param {Object} client The node-mysql client object
 */
function Cassandra(dataSource, settings) {
  this.dataSource = dataSource;
  dataSource.setMaxListeners(Infinity);

  SqlConnector.call(this, 'cassandra', settings);
}

require('util').inherits(Cassandra, SqlConnector);

Cassandra.prototype.connect = function(callback) {
  var self = this;
  var options = generateOptions(this.settings);
  var s = self.settings || {};

  if (this.client) {
    if (callback) {
      process.nextTick(function() {
        callback(null, self.client);
      });
    }
  } else {
    this.client = new cassandra.Client(options);
    this.client.connect(function(err) {
      var conn = self.client.controlConnection.connection;