Fixed some WithinSpan-Bugs and fixed Tests to improve coverage for SpanPositionalQueries
diff --git a/src/main/java/de/ids_mannheim/korap/query/spans/ClassSpans.java b/src/main/java/de/ids_mannheim/korap/query/spans/ClassSpans.java
index 411a50b..b7492e9 100644
--- a/src/main/java/de/ids_mannheim/korap/query/spans/ClassSpans.java
+++ b/src/main/java/de/ids_mannheim/korap/query/spans/ClassSpans.java
@@ -142,7 +142,12 @@
     @Override
     public boolean skipTo (int target) throws IOException {
         classedPayload.clear();
-        if (hasmorespans && spans.doc() < target && spans.skipTo(target))
+
+        if (DEBUG) log.trace("Skip ClassSpans {} -> {}",
+                             spans.doc(), target);
+
+        if (hasmorespans && spans.doc() < target &&
+            spans.skipTo(target))
             return this.addClassPayload();
         return false;
     };