@Test
	public void arithmeticInstrOpcodeTest() {
		try {
			instr = new ArithmeticInstr(Opcode.BR, 10, 20);
		}
		catch (IllegalStateException e) {
			System.out.println(e.getMessage());
		}
		assertNull(instr); //Checks instruction isn't created with invalid opcode for its format.
	}