public static boolean isKotlin(Class clazz) {
        if (kotlin_metadata == null && !kotlin_metadata_error) {
            try {
                kotlin_metadata = Class.forName("kotlin.Metadata");
            } catch (Throwable e) {
                kotlin_metadata_error = true;
            }
        }
        return kotlin_metadata != null && clazz.isAnnotationPresent(kotlin_metadata);
    }
Gets the target constructor and its
parameter names of the specified {@code clazz}

@param clazz the specified class for search
core/src/main/java/com/alibaba/fastjson2/util/KotlinUtils.java