code: function (db, options, cb) {
  	this.db = db;
  	this.cb = cb;
  	this.updateQueryMaker = options.update;
  	this.insertQueryMaker = options.insert;
  	this.maxUpdateAttemptsCount = options.maxUpdateAttemptsCount || 2;
  	this.transform = options.transform;
  	this.insertFirst = !!options.insertFirst;
  	this.nonQuery = !!options.nonQuery;
  
  	var self = this;
  	this.updateAttemptsCount = 0;
  	this.updateOrInsertBound = function () {
  		self.updateOrInsert();
  	};
  }
docs: WARN doesn't support transactions for now