I have a problem with 5th line of my Dockerfile. I couldn't figure out what that means.

```
FROM python:3.7-alpine

LABEL author= APPLE

LABEL company= PINEAPPLE

ARG HOME_DIR='/schooldata'

ADD . $HOME_DIRECT              ##[ this line ]

EXPOSE 5000

WORKDIR $HOME_DIRECT

RUN pip install -r requirements.txt

ENTRYPOINT ["python", "app.py"]

```