/// Returns true if the given String is a valid email address.
bool isValidEmail(String text) {
  return RegExp(
    r'(?<name>[a-zA-Z0-9]+)'
    r'@'
    r'(?<domain>[a-zA-Z0-9]+)'
    r'\.'
    r'(?<topLevelDomain>[a-zA-Z0-9]+)',
  ).hasMatch(text);
}
