I'm trying to sort by an attribute of a class, but I continually get Could not find member errors on my attribute in the sort function. I started by reading several similar questions such as this one, but I still feel I'm doing something incorrectly.
Can anyone explain what would cause this?
My Sorting Attempt:

My class with startTime attribute:

I've also tried several different ways of declaring the airings object. All result in the same "could not find member 'startTime'" error message.
var airings: [Airing] = [Airing]()var airings = [Airing]()var airings = Array<Airing>()var airings: Array<Airing> = []
Any help is greatly appreciated, I'm sure I'm missing something obvious here.