Decrements the value of the current byte at the pointer. If the result is below 0,
        then it will overflow to 255

def _decrement_current_byte(self):
        """
        Decrements the value of the current byte at the pointer. If the result is below 0,
        then it will overflow to 255
        """
        # If the current byte is uninitialized, then decrementing it will make it the max cell size
        # Otherwise, if it's already at the minimum cell size, then it will also make it the max cell size
        if self.tape[self.pointer] is None or self.tape[self.pointer] == self.MIN_CELL_SIZE:
            self.tape[self.pointer] = self.MAX_CELL_SIZE
        else:  # decrement it
            self.tape[self.pointer] -= 1