src/mixin/Eventful.js
function (event, query, handler, context) {
        return on(this, event, query, handler, context, false);
    }
function (event, query, handler, context) {
        return on(this, event, query, handler, context, false);
    }
function ( event , query , handler , context ) { return on ( this , event , query , handler , context , false ) ; }
Bind a handler.

@param {string} event The event name.
@param {string|Object} [query] Condition used on event filter.
@param {Function} handler The event handler.
@param {Object} [context]
Bind a handler .