copy method
Copies this file.
If newPath
is a relative path, it is resolved against
the current working directory (Directory.current).
Returns a Future<File>
that completes
with a File for the copied file.
If newPath
identifies an existing file, that file is
removed first. If newPath
identifies an existing directory, the
operation fails and the future completes with an exception.
Implementation
@override
Future<File> copy(String newPath) {
throw UnimplementedError();
}