static RestClientBuilder builder(String uri) {
        return builder(URI.create(requireNonNull(uri, "uri")));
    }
Returns a new {@link RestClientBuilder} created with the specified base {@code uri}.

@throws IllegalArgumentException if the {@code uri} is not valid or its scheme is not one of the values
                                 in {@link SessionProtocol#httpValues()} or
                                 {@link SessionProtocol#httpsValues()}.
core/src/main/java/com/linecorp/armeria/client/RestClient.java