Header description of variantFittingPresentationWidth: method

VariantFittingPresentationWidth.h

/* 
For strings with length variations, such as from a stringsdict file, this method returns the variant at the given width. 
If there is no variant at the given width, the one for the next smaller width is returned. And if there are none smaller, 
the smallest available is returned. For strings without variations, this method returns self. 
The unit that width is expressed in is decided by the application or framework. But it is intended to be some measurement
indicative of the context a string would fit best to avoid truncation and wasted space.
*/ 
- (NSString *)variantFittingPresentationWidth:(NSInteger)width API_AVAILABLE(macos(10.11), ios(9.0), watchos(2.0), tvos(9.0));