--- a/app/models/TPGraph.java	Fri Mar 08 21:12:37 2013 +0900
+++ b/app/models/TPGraph.java	Sat Mar 09 21:26:40 2013 +0900
@@ -210,8 +210,6 @@
 		}
 		return set.toArray();
 	}
-	
-
 
 	/* 
 	 * Return CLAIM numbers of above [id] CLAIM.
@@ -255,32 +253,30 @@
 		return v;
 	}
 	
-	private void recursiveCopyDownClaimsAndSetLabel(ClaimModel oldUpClaim, ClaimModel latestUpClaim, String... labels) {
+	private void recursiveCopyDownClaimsAndSetLabel(ClaimModel oldUpClaim, ClaimModel latestUpClaim,
+			String timestamp, String... labels) {
 		for (String label: labels) {
 			GremlinPipeline<Vertex, Vertex> pipe = new GremlinPipeline<Vertex, Vertex>();
 			pipe.start(oldUpClaim.getVertex()).out(label);
 			for (Vertex oldDownV : pipe) {
 				ClaimModel oldDownClaim = new ClaimModel(oldDownV);
-				ClaimModel latestDownClaim = oldDownClaim.cloneAndSetLabelPrev();
+				ClaimModel latestDownClaim = oldDownClaim.cloneAndSetLabelPrev(timestamp);
 				setLabel(latestUpClaim.getVertex(), latestDownClaim.getVertex(), label);
-				recursiveCopyDownClaimsAndSetLabel(oldDownClaim, latestDownClaim, labels);
+				recursiveCopyDownClaimsAndSetLabel(oldDownClaim, latestDownClaim, timestamp, labels);
 			}
 		}
 	}
 
-	private ClaimModel copyDownClaims(ClaimModel oldTopClaim) {
-		ClaimModel latestTopClaim = oldTopClaim.cloneAndSetLabelPrev();
-		recursiveCopyDownClaimsAndSetLabel(oldTopClaim, latestTopClaim,
+	private ClaimModel copyDownClaims(ClaimModel oldTopClaim, String timestamp) {
+		ClaimModel latestTopClaim = oldTopClaim.cloneAndSetLabelPrev(timestamp);
+		recursiveCopyDownClaimsAndSetLabel(oldTopClaim, latestTopClaim, timestamp,
 				NodeModel.L_REFUTATION, NodeModel.L_QUESTION, NodeModel.L_SUGGESTION);
 		return latestTopClaim;
 	}
 	
-	/*
-	 * TODO: update TimeStamp
-	 */
-	public ClaimModel copyConsensusTree(ClaimModel claim) {
+	public ClaimModel copyConsensusTree(ClaimModel claim, String timestamp) {
 		ClaimModel oldTopClaim = new ClaimModel(getVertex(getTopClaimVertexId(claim.getId()))); 
-		ClaimModel latestTopClaim = copyDownClaims(oldTopClaim);
+		ClaimModel latestTopClaim = copyDownClaims(oldTopClaim, timestamp);
 		return latestTopClaim;
 	}