private String getRealmName(String realmUrl) {
        return StringUtils.substringAfter(realmUrl, "/realms/").trim();
    }
@see io.apiman.gateway.engine.policies.AbstractMappedPolicy#doApply(io.apiman.gateway.engine.beans.ApiRequest,
     io.apiman.gateway.engine.policy.IPolicyContext, java.lang.Object,
     io.apiman.gateway.engine.policy.IPolicyChain)
plugins/keycloak-oauth-policy/src/main/java/io/apiman/plugins/keycloak_oauth_policy/KeycloakOauthPolicy.java