public URI httpUri(SerializationFormat format) {
        return delegate.httpUri(format);
    }
Returns the HTTP {@link URI} for the {@link Server}.

@return the absolute {@link URI} without a path.
@throws IllegalStateException if the {@link Server} is not started or
                              it did not open an HTTP port.
junit5/src/main/java/com/linecorp/armeria/testing/junit5/server/ServerExtension.java