public URI uri(SessionProtocol protocol) {
        return delegate.uri(protocol);
    }
Returns the {@link URI} for the {@link Server} of the specified {@link SessionProtocol}.

@return the absolute {@link URI} without a path.
@throws IllegalStateException if the {@link Server} is not started or
                              it did not open the port for the specified {@link SessionProtocol}.
junit4/src/main/java/com/linecorp/armeria/testing/junit4/server/ServerRule.java