SaslCredentialsInput.plain constructor
PLAIN: a username and password sent in the clear. Only safe once the connection is over
TLS, since nothing else protects them.
Implementation
factory SaslCredentialsInput.plain({required String username, required String password}) {
return SaslCredentialsInput._({
'mechanism': 'plain',
'username': username,
'password': password,
});
}