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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def fetch_open_data(cls, flag, start, end, **kwargs):
 """Fetch Open Data timeline segments into a flag. flag : `str` the name of the flag to query start : `int`, `str` the GPS start time (or parseable date string) to query end : `int`, `str` the GPS end time (or parseable date string) to query verbose : `bool`, optional show verbose download progress, default: `False` timeout : `int`, optional timeout for download (seconds) host : `str`, optional URL of LOSC host, default: ``'losc.ligo.org'`` Returns ------- flag : `DataQualityFlag` a new flag with `active` segments filled from Open Data Examples -------- <DataQualityFlag('H1:DATA', description=None)> """

        start = to_gps(start).gpsSeconds
        end = to_gps(end).gpsSeconds
        known = [(start, end)]
        active = timeline.get_segments(flag, start, end, **kwargs)
        return cls(flag.replace('_', ':', 1), known=known, active=active,
                   label=flag)