def start_output (self):
        """Write checking start info as csv comment."""
        super(CSVLogger, self).start_output()
        row = []
        if self.has_part("intro"):
            self.write_intro()
            self.flush()
        else:
            # write empty string to initialize file output
            self.write(u"")
        self.queue = StringIO()
        self.writer = csv.writer(self.queue, dialect=self.dialect,
               delimiter=self.separator, lineterminator=self.linesep,
               quotechar=self.quotechar)
        for s in Columns:
            if self.has_part(s):
                row.append(s)
        if row:
            self.writerow(row)
Write checking start info as csv comment.