final class HandshakeCalculator {



}

@@ -1,8 +1,32 @@
+import java.util.List;%0A%0A
 final cl
@@ -52,12 +52,176 @@
 ator %7B%0A%0A
+    List%3CSignal%3E calculateHandshake(int number) %7B%0A        throw new UnsupportedOperationException(%22Delete this statement and write your own implementation.%22);%0A    %7D
 %0A%0A%7D%0A

update starter implementation