tracks/java/exercises/difference-of-squares/src/main/java/DifferenceOfSquaresCalculator.java in trackler-2.1.0.11 vs tracks/java/exercises/difference-of-squares/src/main/java/DifferenceOfSquaresCalculator.java in trackler-2.1.0.12

@@ -1,5 +1,15 @@
-public final class DifferenceOfSquaresCalculator {
+final class DifferenceOfSquaresCalculator {
 
+    int computeSquareOfSumTo(final int input) {
+        throw new UnsupportedOperationException("Delete this statement and write your own implementation.");
+    }
 
+    int computeSumOfSquaresTo(final int input) {
+        throw new UnsupportedOperationException("Delete this statement and write your own implementation.");
+    }
+
+    int computeDifferenceOfSquares(final int input) {
+      throw new UnsupportedOperationException("Delete this statement and write your own implementation.");
+    }
 
 }