vasyabigi/angular-slick — pull request #40 by i8ramin (2014-12-03 16:11:37+00:00)
Title: Change nulls to undefined

According to the docs, jquery extend will not copy over undefined properties, but will copy over "null" properties. We don't want null properties here so that the slick defaults are used.

http://api.jquery.com/jquery.extend/

simple test here:
http://jsfiddle.net/12kwnk4k/3/