private BlockTree createSampleTree1(){
		
		WeightedIdentity t1 = new WeightedIdentity("t1",10.0, "blue");
		WeightedIdentity t2 = new WeightedIdentity("t2",10.0, "red");
		WeightedIdentity t3 = new WeightedIdentity("t3",10.0, "green");

		// create a bunch of blocks
		
		SignedBlock sb1 = new SignedBlock( null, t1 );
		SignedBlock sb2 = new SignedBlock( sb1, t2 );
		SignedBlock sb3 = new SignedBlock( sb1, t3 );
		SignedBlock sb4 = new SignedBlock( sb2, t1 );
					sb5 = new SignedBlock( sb4, t2 );
		SignedBlock sb6 = new SignedBlock( sb4, t3 );
		SignedBlock sb7 = new SignedBlock( sb4, t1 );
		SignedBlock sb8 = new SignedBlock( sb6, t2 );
		SignedBlock sb9 = new SignedBlock( sb6, t1 );
		SignedBlock sb10 = new SignedBlock( sb6, t3 );


		
		// create a BlockTree
		
		BlockTree myTree = new BlockTree(sb1);
		try {
			
			myTree.addBlock(sb2);
			myTree.addBlock(sb3);
			myTree.addBlock(sb4);
			
			myTree.printDOT("tree1.svg");
			
			myTree.addBlock(sb5);
			myTree.addBlock(sb6);
			myTree.addBlock(sb7);
			
			myTree.printDOT("tree2.svg");

			myTree.addBlock(sb8);
			myTree.addBlock(sb9);
			myTree.addBlock(sb10);
			
			myTree.printDOT("tree3.svg");
			
			System.out.println("\n\nhighest confidence score "+myTree.mostConfidentChainScore);

			// now attempt to get best block for identity t1
			
			SignedBlock newBlock = myTree.createBestBlock( t1 );
			myTree.addBlock( newBlock );
			myTree.printDOT("tree4.svg");
			
			SignedBlock newBlock2 = myTree.createBestBlock( t2 );
			myTree.addBlock( newBlock2 );
			myTree.printDOT("tree5.svg");
			
			SignedBlock newBlock3 = myTree.createBestBlock( t3 );
			myTree.addBlock( newBlock3 );
			myTree.printDOT("tree6.svg");
			
			SignedBlock newBlock4 = myTree.createBestBlock( t3 );
			myTree.addBlock( newBlock4 );
			myTree.printDOT("tree7.svg");


			
			
		} catch (BlockHasNoPreviousException e) {
			
			fail("malformed blocks");
			
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		
		return myTree;
		
	}