private static OAuth2FlowType toEnum(String flowType) {
        return EnumUtils.getEnum(OAuth2FlowType.class, flowType.toUpperCase());
    }
@author Marc Savy {@literal <marc@rhymewithgravy.com>}
gateway/platforms/vertx3/vertx3/src/main/java/io/apiman/gateway/platforms/vertx3/api/auth/KeycloakOAuthFactory.java