docs: function MongoStore(connection, options) {
  	if(arguments.length === 0 || typeof arguments[0] !== 'string') {
  		throw new Error('A valid connection string has to be provided');
  	}
  
  	TokenStore.call(this);
  
  	this._options = options || {};
  	this._collectionName = 'passwordless-token';
  	if(this._options.mongostore) {
  		if(this._options.mongostore.collection) {
  			this._collectionName = this._options.mongostore.collection;
  		}
  		delete this._options.mongostore;
  	}
  
  	this._uri = connection;
  	this._db = null;
  	this._collection = null;
  }