fileStem method
Extracts the portion of the file name before the last "." -
None/null, if there is no file name; The entire file name if there is no embedded .; The entire file name if the file name begins with . and has no other .s within; Otherwise, the portion of the file name before the final .
Implementation
String? fileStem() => Env.isWindows
? WindowsPath(_string).fileStem()
: UnixPath(_string).fileStem();