private static ServiceConfigurationError fail(final Class<?> service, final URL url, final int line,
                                                  final String msg) {
        return fail(service, url + ":" + line + ": " + msg);
    }
A simple service-provider loading facility (SPI).

@author jiachun.fjc
jraft-core/src/main/java/com/alipay/sofa/jraft/util/JRaftServiceLoader.java