Would we ever want to examine operations' dependencies, for example, to determine which oauth2 operation served as its dependency.

https://developer.apple.com/library/mac/documentation/Cocoa/Reference/NSOperation_class/Reference/Reference.html#//apple_ref/occ/instm/NSOperation/dependencies

"Operations are not removed from this dependency list as they finish executing. You can therefore use this list to track all dependent operations, including those that have already finished executing. The only way to remove an operation from this list is to use the removeDependency: method."

So by adding the dependency even after the operation was already finished, we might be introducing some false signals. Probably over-thinking. Please don't let this block you from merging.