static WebClientBuilder builder(SessionProtocol protocol, EndpointGroup endpointGroup, String path) {
        requireNonNull(protocol, "protocol");
        requireNonNull(endpointGroup, "endpointGroup");
        requireNonNull(path, "path");
        return new WebClientBuilder(protocol, endpointGroup, path);
    }
Returns a new {@link WebClientBuilder} created with the specified {@link SessionProtocol},
base {@link EndpointGroup} and path.

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