src/mixin/Eventful.js
function (event, query, handler, context) {
        return on(this, event, query, handler, context, true);
    }
function (event, query, handler, context) {
        return on(this, event, query, handler, context, true);
    }
function ( event , query , handler , context ) { return on ( this , event , query , handler , context , true ) ; }
The handler can only be triggered once, then removed.

@param {string} event The event name.
@param {string|Object} [query] Condition used on event filter.
@param {Function} handler The event handler.
@param {Object} context
The handler can only be triggered once then removed .