Add sample func

demo/src/main/kotlin/com/example/demo/DemoApplication.kt

@@ -1,6 +1,7 @@
 package com.example.demo
 
 import com.example.lib.MyLib
+import com.example.lib.MyUtils
 import org.springframework.boot.CommandLineRunner
 import org.springframework.boot.autoconfigure.SpringBootApplication
 import org.springframework.boot.runApplication
@@ -9,6 +10,8 @@ import org.springframework.boot.runApplication
 class DemoApplication : CommandLineRunner {
     override fun run(vararg args: String?) {
         MyLib.doOnMe()
+
+        println("Hello JJKK: ${MyUtils.helloWorld()}")
     }
 }