Because the calls are now evenly balanced, the try/catch is no longer necessary. Try/catch is also not very idiomatic Objective-C, as described in [Exception Programming Topics](https://developer.apple.com/library/ios/documentation/Cocoa/Conceptual/Exceptions/Exceptions.html#//apple_ref/doc/uid/10000012-BAJGFBFB):

> Important: You should reserve the use of exceptions for programming or unexpected runtime errors such as out-of-bounds collection access, attempts to mutate immutable objects, sending an invalid message, and losing the connection to the window server. You usually take care of these sorts of errors with exceptions when an application is being created rather than at runtime.

and 

> The Cocoa frameworks are generally not exception-safe. The general pattern is that exceptions are reserved for programmer error only, and the program catching such an exception should quit soon afterwards.

NSHipster (from the same [KVO article](http://nshipster.com/key-value-observing/)) also agrees that catching the exception should be used as a last resort:

> Granted, not handling a caught exception, as in this example, is waving the [UIColor whiteColor] flag of surrender. Therefore, one should only really use this technique when faced with intermittent crashes which cannot be remedied by normal book-keeping (whether due to race conditions or undocumented behavior from a superclass).