Function parse_since_from_explain

test/cluster/mzcompose.py:3348–3354

(explain: str)

        return table_since, index_since

    def parse_since_from_explain(explain: str) -> int:
        since_line = re.compile(r"\s*read frontier:\[(?P<since>\d+) \(.+\)\]")
        for line in explain.splitlines():
            if match := since_line.match(line):
                return int(match.group("since"))

        raise AssertionError(f"since not found in explain: {explain}")

    def validate_since(since: int, name: str) -> None:
        now = datetime.now()