def _parse_date(string: str) -> '<STR_LIT>':
try:<EOL><INDENT>return datetime.datetime.strptime(string, '<STR_LIT>').date()<EOL><DEDENT>except ValueError:<EOL><INDENT>return None<EOL><DEDENT>
Parse an ISO 8601 date (YYYY-mm-dd).

    Returns None if parsing fails.

    >>> _parse_date('1990-01-02')
    datetime.date(1990, 1, 2)
    >>> _parse_date('foo') is None
    True