Forces the receiver to perform layout for the specified glyph range, if it has not already done so.
- iOS 7.0+
- macOS 10.5+
- tvOS 9.0+
The glyph range for which layout is performed.
The layout manager reserves the right to perform layout for larger ranges. If noncontiguous layout is disabled, then the affected range is always effectively extended to start at the beginning of the text.