Map an array of arrays
<p>Is there a method in lodash to map over an array of arrays</p>

<p>I would like to do something like this so that it keeps the structure of the array.</p>

<pre><code>def double(x) { return x*2 }

_([[1,2],[3,4]]).somemethod(double) == [[2,4],[6,8]]
</code></pre>