private String toClassName(String fullQualifiedMethodName) {
        final int classEndPosition = fullQualifiedMethodName.lastIndexOf('.');
        if (classEndPosition <= 0) {
            throw new IllegalArgumentException("invalid full qualified method name(" + fullQualifiedMethodName + "). not found method");
        }

        return fullQualifiedMethodName.substring(0, classEndPosition);
    }
@author Harris Gwag (gwagdalf)
@author Taejin Koo
agent-module/plugins/kafka/src/main/java/com/navercorp/pinpoint/plugin/kafka/KafkaPlugin.java