private String getClassName(String apiDescription, int classIndex) {
        if (classIndex == -1) {
            return "";
        } else {
            return parseClassName(apiDescription, classIndex);
        }
    }
Similar to MethodDescriptor, but instead parses string-based values.
@author emeroad
commons-server/src/main/java/com/navercorp/pinpoint/common/server/trace/ApiDescriptionParser.java