parse method
      
void
parse()
      
     
    
    
Implementation
void parse() {
  if (_parsed != null) return;
  final parsed = <String, String>{};
  final consecutive = <String>[];
  for (final flag in _flags) {
    if (flag.startsWith('-')) {
      if (consecutive.isNotEmpty) {
        parsed[consecutive.first] = consecutive.join(' ');
      }
      consecutive.clear();
      if (flag.contains('=')) {
        final split = flag.split('=');
        parsed[split.first] = flag;
        continue;
      }
    }
    consecutive.add(flag);
  }
  if (consecutive.isNotEmpty) {
    parsed[consecutive.first] = consecutive.join(' ');
  }
  _parsed = parsed;
}