@Override
        public Credentials getCredentials() {
            return credentials;
        }
Returns a Map containing all GuacamoleConfigurations that this user
is authorized to use. The keys of this Map are Strings which
uniquely identify each configuration.

@return
    A Map of all configurations for which this user is authorized.
guacamole-ext/src/main/java/org/apache/guacamole/net/auth/simple/SimpleAuthenticationProvider.java