@Test
	public void testAddBlock() {
		
		// create a copy of the chain
		BlockChain newChain = new BlockChain(testChain);
	
		// add a block
		newChain.addBlock( new SignedBlock(null, ctrptyID1) );
		
		// test to see that the length of new is 1 more than length of first
		assertTrue("Chain copy with block added has 1 more length than original", 
				testChain.chain.size() == newChain.chain.size() -1
		);

		
	}