add lombok

src/main/java/com/imyeyu/spring/util/YamlPropertySourceFactory.java

@@ -25,6 +25,6 @@ public class YamlPropertySourceFactory implements PropertySourceFactory {
     @Override
     public @org.springframework.lang.NonNull PropertySource<?> createPropertySource(String name, EncodedResource resource) throws IOException {
         List<PropertySource<?>> sources = new YamlPropertySourceLoader().load(resource.getResource().getFilename(), resource.getResource());
-        return sources.get(0);
+        return sources.getFirst();
     }
 }