implemented necassary test case

Former-commit-id: d1115558dc86f88372ee815300c688f719934f18

dependency-check-core/src/main/java/org/owasp/dependencycheck/data/lucene/TokenPairConcatenatingFilter.java

@@ -47,6 +47,24 @@ public final class TokenPairConcatenatingFilter extends TokenFilter {
      */
     private final LinkedList<String> words;
 
+    /**
+     * Returns the previous word. This is needed in the test cases.
+     *
+     * @return te previous word
+     */
+    protected String getPreviousWord() {
+        return previousWord;
+    }
+
+    /**
+     * Returns the words list. This is needed in the test cases.
+     *
+     * @return the words list
+     */
+    protected LinkedList<String> getWords() {
+        return words;
+    }
+
     /**
      * Constructs a new TokenPairConcatenatingFilter.
      *