@Override
    public void setup(ProfilerPluginSetupContext context) {
        
        final LogbackConfig config = new LogbackConfig(context.getConfig());
        if (!config.isLogbackLoggingTransactionInfo()) {
            logger.info("{} disabled", this.getClass().getSimpleName());
            return;
        }
        logger.info("{} config:{}", this.getClass().getSimpleName(), config);
        
        transformTemplate.transform("ch.qos.logback.classic.spi.LoggingEvent", LoggingEventTransform.class);
        if (config.isPatternReplaceEnable()) {
            transformTemplate.transform("ch.qos.logback.core.pattern.PatternLayoutBase", LoggingPatternTransform.class);
        }
    }
This modifier support slf4j 1.4.1 version and logback 0.9.8 version, or greater.
Because package name of MDC class is different on under those version 
and under those version is too old.
By the way slf4j 1.4.0 version release on May 2007.
Refer to url http://mvnrepository.com/artifact/org.slf4j/slf4j-api for detail.

@author minwoo.jung
@author yjqg6666
agent-module/plugins/logback/src/main/java/com/navercorp/pinpoint/plugin/logback/LogbackPlugin.java