addExport method
And an export.
Implementation
void addExport(String url, {List<String> members = const []}) {
final directive = members.isNotEmpty
? "export '$url' show ${members.join(', ')};"
: "export '$url';";
if (url.startsWith('package:')) {
_packageExports.add(directive);
} else {
_fileExports.add(directive);
}
}