in dubbo-error-code-inspector/src/main/java/org/apache/dubbo/errorcode/extractor/JavassistConstantPoolErrorCodeExtractor.java [38:46]
public List<String> getErrorCodes(String classFilePath) {
ClassFile clsF = JavassistUtils.openClassFile(classFilePath);
ConstPool cp = clsF.getConstPool();
List<String> cpItems = JavassistUtils.getConstPoolStringItems(cp);
return cpItems.stream().filter(x -> ERROR_CODE_PATTERN.matcher(x).matches()).collect(Collectors.toList());
}