@Test
	public void arithmeticInstr_testInvalidDestinationRegisterRef() { //Checks instr. not created with invalid register ref.
		try {
			instr = new ArithmeticInstr(Opcode.ADD, 5, 25);
		}
		catch (IllegalStateException e) {
			System.out.println(e.getMessage());
		}
		assertNull(instr);
	}