move instanceof code

core-java/src/main/java/com/baeldung/keyword/Circle.java

@@ -1,5 +0,0 @@
-package com.baeldung.keyword;
-
-public class Circle extends Round implements Shape {
-
-}

core-java/src/main/java/com/baeldung/keyword/Ring.java

@@ -1,4 +0,0 @@
-package com.baeldung.keyword;
-
-public class Ring extends Round {
-}

core-java/src/main/java/com/baeldung/keyword/Round.java

@@ -1,4 +0,0 @@
-package com.baeldung.keyword;
-
-public class Round {
-}

core-java/src/main/java/com/baeldung/keyword/Shape.java

@@ -1,4 +0,0 @@
-package com.baeldung.keyword;
-
-public interface Shape {
-}

core-java/src/main/java/com/baeldung/keyword/Triangle.java

@@ -1,4 +0,0 @@
-package com.baeldung.keyword;
-
-public class Triangle implements Shape {
-}