A key for the image tiles size. The associated value is an NSArray that containsNSNumber objects for the dimensions of the image tiles requested from the image provider.
Available in Mac OS X v10.4 and later.
Declaration Syntax Version Information- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)