generate method
Implementation
Future<void> generate() async {
_checkFiles();
final found = _findAnnotatedLibraries().toSet();
_filePaths.removeWhere((e) => !found.contains(e));
final libraryResults = await _analyze(_filePaths);
final implementations = _collectMetaImplementations(libraryResults.values);
await _buildMetaExpressions(libraryResults, implementations);
}