From 4b368750f911c182ddce6c41fb3b78b90fd5c622 Mon Sep 17 00:00:00 2001
From: Jeremy Ashkenas Object Functions
Returns true if object is NaN.
Note: this is not
the same as the native isNaN function, which will also return
- true if the variable is undefined.
+ true for many other not-number values, such as undefined.
_.isNaN(NaN);