/// 
///
/// See also:
///
/// * [Typography]
/// * [Theme]
/// * [ThemeData]
/// * [Typography], the class that generates [TextTheme]s appropriate for a platform.
/// * [Theme], for other aspects of a material design application that can be
/// See also [applyBoxFit], which applies the sizing semantics of these values
/// (though not the alignment semantics).
///
/// The following diagrams show the effects of each value:
///
/// 
///
/// 
///
/// 
///
/// 
///
/// 
///
/// 
///
/// 
enumBoxFit{
/// Fill the target box by distorting the source's aspect ratio.