hasSpecialCharacters = password.contains(new RegExp(r'[!@#$%^&*(),.?":{}|<>]')); 

  final bool isNumeric = password.contains(RegExp('[0-9]'));
  final bool isLowerCase = password.contains(RegExp("(?:[^a-z]*[a-z]){1}"));
  final bool isUpperCase = password.contains(RegExp("(?:[^A-Z]*[A-Z]){1}"));