public static ClientPreprocessors ofRpc(RpcPreprocessor preprocessor) {
        return builder().addRpc(preprocessor).build();
    }
Creates a new instance from a single {@link RpcPreprocessor}.

@param preprocessor the {@link RpcPreprocessor} that transforms an {@link RpcPreClient}
                    to another
core/src/main/java/com/linecorp/armeria/client/ClientPreprocessors.java