Returns the value associated with a given key.
Original signature is '- (id)objectForKey:(id)aKey'
Available in Mac OS X v10.0 and later.


- aKey (Id)
- The key for which to return the corresponding value.

The value associated with aKey, or nil if no value is associated with aKey.

- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)