public URI getRedirectURI() throws GuacamoleException {
        return environment.getRequiredProperty(CASGuacamoleProperties.CAS_REDIRECT_URI);
    }
Returns the URI that the CAS service should redirect to after
the authentication process is complete, as configured with
guacamole.properties. This must be the full URL that a user would enter
into their browser to access Guacamole.

@return
    The URI to redirect the client back to after authentication
    is completed, as configured in guacamole.properties.

@throws GuacamoleException
    If guacamole.properties cannot be parsed, or if the redirect URI
    property is missing.
extensions/guacamole-auth-sso/modules/guacamole-auth-sso-cas/src/main/java/org/apache/guacamole/auth/cas/conf/ConfigurationService.java