Quoting this link from effective dart

A good documentation looks like:

/// Deletes the file at [path].
///
/// Throws an [IOError] if the file could not be found. Throws a
/// [PermissionError] if the file is present but could not be deleted.

But in the Gallery source file, I have seen many places where this is not followed, here are few links from adaptive.dart file:

Link 1
Link 2
Link 3