Phaser button handler function with parameter
<p>I'm using Phaser.js to build an html game. This maybe more of a general javascript question but I'm using Phaser as context, so I try to setup a button with handler, here's the button definition in main.js:</p>

<pre><code>var someParam = 2;
var btn = game.add.button(0, 0, 'playButton', actions.handler, this, 1, 0, 1);
</code></pre>

<p>And in another file named actions.js, I defined the handler function:</p>

<pre><code>var handler = function(someParam) {
    console.log(someParam);
};
module.exports = {
    handler: handler
};
</code></pre>

<p>Question is how can I pass that someParam into the handler function?</p>