Added isReaderOpen method.

Change-Id: Ia084d1a9c75755dfb6cacb96310caa8665aab209
diff --git a/src/main/java/de/ids_mannheim/korap/KrillIndex.java b/src/main/java/de/ids_mannheim/korap/KrillIndex.java
index 976fe86..aecbf30 100644
--- a/src/main/java/de/ids_mannheim/korap/KrillIndex.java
+++ b/src/main/java/de/ids_mannheim/korap/KrillIndex.java
@@ -1893,4 +1893,8 @@
         mc.close();
         return mc;
     };
+    
+    public boolean isReaderOpen () {
+        return readerOpen;
+    }
 };