text java createwordlist method clean up

src/Text.java

@@ -140,7 +140,7 @@ public class Text {
      */
     public ArrayList<String> index() {
         HashMap<String,ArrayList<Integer>> wordbook = new HashMap<>();
-        wordbook = createWordlist(wordbook);
+        createWordlist(wordbook);
         String input;
         ArrayList<String> output = new ArrayList<>();
         ArrayList<Integer> values;
@@ -168,7 +168,7 @@ public class Text {
      *
      * @return HashMap<String, ArrayList < Integer>>
      */
-    private HashMap<String, ArrayList<Integer>> createWordlist(HashMap<String,ArrayList<Integer>> wordbook) {
+    private void createWordlist(HashMap<String,ArrayList<Integer>> wordbook) {
         int counter;
         ArrayList<Integer> numbersList;
         String firstLetter;
@@ -187,7 +187,6 @@ public class Text {
                     counter = numbersList.get(0);
                     numbersList.remove(0);
                     numbersList.add(0, counter + 1);
-
                     if (numbersList.get(numbersList.size() - 1) < i + 1) {
                         numbersList.add(i + 1);
                     }
@@ -199,7 +198,6 @@ public class Text {
                 wordbook.put(word, numbersList);
             }
         }
-        return wordbook;
     }
 
 }