added OutputToList source

src/main/java/edu/luc/cs/consoleapp/MainLeaky.java

@@ -39,7 +39,8 @@ public static void main(final String[] args) {
     }
 
     final var input = new Scanner(System.in).useDelimiter("(?U)[^\\p{Alpha}0-9']+");
-    final var result = new LeakyQueue(lastNWords, input).process();
+    final var coreLogic = new LeakyQueue(lastNWords, input);
+    final var result = coreLogic.process();
 
     result.forEach(
       value -> {
@@ -55,6 +56,8 @@ public static void main(final String[] args) {
    * A sliding window queue that retains the last N elements. 
    * This component is independent of the user interface and can be tested independently.
    * Nevertheless, it violates an important nonfunctional requirement: it leaks memory.
+   * In addition, it violates the functional requirement of 
+   * interactively responding to each input.
    */
   static class LeakyQueue {
 

src/test/java/edu/luc/cs/consoleapp/OutputToList.java

@@ -0,0 +1,17 @@
+package edu.luc.cs.consoleapp;
+
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Queue;
+
+class OutputToList implements OutputHandler {
+
+  final List<Queue<String>> result = new ArrayList<>();
+
+  @Override
+  public void accept(final Queue<String> value) {
+    final var snapshot = new LinkedList<>(value);
+    result.add(snapshot);
+  }
+}