@Test 
	public void branchInstrInvalidOpcodeTest() { //To test instruction is not created with illegal opcode for format
		try {
			instr = new BranchInstr(Opcode.ADD, 0);
		}
		catch (IllegalStateException e) {
			System.out.println(e.getMessage());
		}
		assertNull(instr); //instr should still be null if creation has failed, which it should because of invalid opcode		
	}