ReactJS Mixin Method Override

How can I create a method on a ReactJS Mixin such that I'm allowed to override it in the Component definition?

by Jon Beebe

HTML

<script src="http://fb.me/JSXTransformer-0.10.0.js"></script>
<script src="http://fb.me/react-with-addons-0.10.0.js"></script>
<script src="http://fb.me/react-js-fiddle-integration.js"></script>

JavaScript 1.7

/** @jsx React.DOM */

var MyMixin = {
    render: function () {
        return this.renderItem();
    },
    renderItem: function () {
        return <div>Hello {this.props.name}</div>;
    }
};

var Hello = React.createClass({
    mixins: [MyMixin],
    renderItem: function() {
        return <div>Hey {this.props.name}</div>;
    }
});

React.renderComponent(<Hello name="World" />, document.body);
 
// Notice in the console an error is logged: 

/*
Uncaught Error: Invariant Violation: ReactCompositeComponentInterface: You are attempting to define `renderItem` on your component more than once. This conflict may be due to a mixin.
*/