public HealthCheckServiceBuilder updatable(HealthCheckUpdateHandler updateHandler) {
        this.updateHandler = requireNonNull(updateHandler, "updateHandler");
        return this;
    }
Specifies a {@link HealthCheckUpdateHandler} which handles other HTTP methods than {@code HEAD} and
{@code GET} which updates the healthiness of the {@link Server}. This feature is disabled by default.
It is recommended to employ some authorization mechanism such as {@link AuthService}
when enabling this feature.

@param updateHandler The {@link HealthCheckUpdateHandler} which handles {@code PUT}, {@code POST} or
                     {@code PATCH} requests and tells if the {@link Server} needs to be marked as
                     healthy or unhealthy.
@see #updatable(boolean)
core/src/main/java/com/linecorp/armeria/server/healthcheck/HealthCheckServiceBuilder.java