Merged PR 130: Added null pointer tracking for Rag

Added null pointer tracking for Rag

src/main/java/com/olympus/hermione/stepSolvers/AdvancedQueryRagSolver.java

@@ -290,7 +290,10 @@ public class AdvancedQueryRagSolver extends StepSolver {
         }
 
 
-        docs = docs.stream().collect(Collectors.toMap(Document::getId, d -> d, (d1, d2) -> d1)).values().stream().collect(Collectors.toList());
+        docs = docs.stream()
+            .filter(d -> d.getMetadata().get("KsDocumentId") != null)
+            .filter(d -> d.getMetadata().get("KsDocumentIndex") != null)
+            .collect(Collectors.toMap(Document::getId, d -> d, (d1, d2) -> d1)).values().stream().collect(Collectors.toList());
 
         //Sort by KsDocumentId and KsDocumentIndex
         docs.sort((d1, d2) -> {