def _convert_missing(context: Literal["html"], el: str):
    """Convert el to a context specific representation."""

    # TODO: how is context passed? Could use a literal string (e.g. "html") for now?
    # TODO: detect if el has some kind of AsIs feature specified
    # which indicates it should not be converted

    # If a table row has all empty cells, they collapse. So add a single line break.
    # See https://stackoverflow.com/q/2789372/1144523
    if context == "html" and el == "":
        return "<br />"

    return el
Convert el to a context specific representation.
great_tables/_substitution.py