A `GtkSourceFile` object is the on-disk representation of a [class@Buffer]. With a `GtkSourceFile`, you can create and configure a [
class@FileLoader] and [class@FileSaver] which take by default the values of the `GtkSourceFile` properties (except for the file loader
which auto-detect some properties). On a successful load or save operation, the `GtkSourceFile` properties are updated. If an operation
fails, the `GtkSourceFile` properties have still the previous valid values.