private BiFunction<FromSourceLocation, String, ValidationEvent> getEventEmitter() {
            return (sourceLocation, message) -> error(serviceShape, sourceLocation, message);
        }
Validator which verifies an endpoint with an authSchemes property conforms to a strict schema.
smithy-rules-engine/src/main/java/software/amazon/smithy/rulesengine/validators/RuleSetAuthSchemesValidator.java