usageLineLength property Null safety
An optional maximum line length for usage messages.
If specified, then help messages in the usage are wrapped at the given column, after taking into account the width of the options. Will refuse to wrap help text to less than 10 characters of help text per line if there isn't enough space on the line. It preserves embedded newlines, and attempts to wrap at whitespace breaks (although it will split words if there is no whitespace at which to split).
If null (the default), help messages are not wrapped.
@override int? get usageLineLength => null;