diff --git a/genomix/genomix-data/src/main/java/edu/uci/ics/genomix/type/NodeWritable.java b/genomix/genomix-data/src/main/java/edu/uci/ics/genomix/type/NodeWritable.java
index baace6a..4f1e0ef 100644
--- a/genomix/genomix-data/src/main/java/edu/uci/ics/genomix/type/NodeWritable.java
+++ b/genomix/genomix-data/src/main/java/edu/uci/ics/genomix/type/NodeWritable.java
@@ -41,6 +41,7 @@
         public static final byte DIR_RF = 0b10 << 0;
         public static final byte DIR_RR = 0b11 << 0;
         public static final byte DIR_MASK = 0b11 << 0;
+        public static final byte DIR_CLEAR = 0b1111100 << 0;
         
         public static final byte[] values = {DIR_FF, DIR_FR, DIR_RF, DIR_RR};
     }
diff --git a/genomix/genomix-pregelix/src/main/java/edu/uci/ics/genomix/pregelix/graph/GenerateGraphViz.java b/genomix/genomix-pregelix/src/main/java/edu/uci/ics/genomix/pregelix/graph/GenerateGraphViz.java
index a4b6f4f..7d489e9 100644
--- a/genomix/genomix-pregelix/src/main/java/edu/uci/ics/genomix/pregelix/graph/GenerateGraphViz.java
+++ b/genomix/genomix-pregelix/src/main/java/edu/uci/ics/genomix/pregelix/graph/GenerateGraphViz.java
@@ -50,7 +50,7 @@
                 gv.addln(outputEdge);
                 /** add readIdSet **/
                 outputNode += " [shape=record, label = \"<f0> " + key.toString() 
-                        + "|<f1> " + value.getThreadList(DirectionFlag.DIR_FF).printReadIdSet()
+//                        + "|<f1> " + value.getThreadList(DirectionFlag.DIR_FF).printReadIdSet()
                         + "\"]\n";
                 gv.addln(outputNode);
             }
@@ -96,7 +96,7 @@
                 gv.addln(outputEdge);
                 /** add readIdSet **/
                 outputNode += " [shape=record, label = \"<f0> " + key.toString() 
-                        + "|<f1> " + value.getNodeIdList().printReadIdSet()
+//                        + "|<f1> " + value.getNodeIdList().printReadIdSet()
                         + "\"]\n";
                 gv.addln(outputNode);
             }
diff --git a/genomix/genomix-pregelix/src/main/java/edu/uci/ics/genomix/pregelix/type/DirFlag.java b/genomix/genomix-pregelix/src/main/java/edu/uci/ics/genomix/pregelix/type/DirFlag.java
index 5e262ba..aeb6caf 100644
--- a/genomix/genomix-pregelix/src/main/java/edu/uci/ics/genomix/pregelix/type/DirFlag.java
+++ b/genomix/genomix-pregelix/src/main/java/edu/uci/ics/genomix/pregelix/type/DirFlag.java
@@ -2,12 +2,20 @@
 
 import edu.uci.ics.genomix.pregelix.io.VertexValueWritable.State;
 
-public class DirFlag extends State {
-//    public static final byte DIR_NO = 0b000 << 0;
-    public static final byte DIR_FF = 0b001 << 0;
-    public static final byte DIR_FR = 0b010 << 0;
-    public static final byte DIR_RF = 0b011 << 0;
-    public static final byte DIR_RR = 0b100 << 0;
-    public static final byte DIR_MASK = 0b111 << 0;
-    public static final byte DIR_CLEAR = 0b1111000 << 0;
+public class DirFlag extends State{
+    public static final byte DIR_FF = 0b00 << 0;
+    public static final byte DIR_FR = 0b01 << 0;
+    public static final byte DIR_RF = 0b10 << 0;
+    public static final byte DIR_RR = 0b11 << 0;
+    public static final byte DIR_MASK = 0b11 << 0;
+    public static final byte DIR_CLEAR = 0b1111100 << 0;
 }
+//public class DirFlag extends State {
+////    public static final byte DIR_NO = 0b000 << 0;
+//    public static final byte DIR_FF = 0b001 << 0;
+//    public static final byte DIR_FR = 0b010 << 0;
+//    public static final byte DIR_RF = 0b011 << 0;
+//    public static final byte DIR_RR = 0b100 << 0;
+//    public static final byte DIR_MASK = 0b111 << 0;
+//    public static final byte DIR_CLEAR = 0b1111000 << 0;
+//}
diff --git a/genomix/genomix-pregelix/src/test/resources/only_pathmerge.txt b/genomix/genomix-pregelix/src/test/resources/only_pathmerge.txt
index 5a15ca0..a789948 100644
--- a/genomix/genomix-pregelix/src/test/resources/only_pathmerge.txt
+++ b/genomix/genomix-pregelix/src/test/resources/only_pathmerge.txt
@@ -1 +1,2 @@
+P4ForMergeGraph.xml
 LogAlgorithmForMergeGraph.xml