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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 parse_time(timestring):
 """Attepmts to parse an ISO8601 formatted ``timestring``. Returns a ``datetime.datetime`` object. """

    timestring = str(timestring).strip()

    for regex, pattern in TIME_FORMATS:
        if regex.match(timestring):
            found = regex.search(timestring).groupdict()

            dt = datetime.utcnow().strptime(found['matched'], pattern)
            dt = datetime.combine(date.today(), dt.time())

            if 'fraction' in found and found['fraction'] is not None:
                dt = dt.replace(microsecond=int(found['fraction'][1:]))

            if 'timezone' in found and found['timezone'] is not None:
                dt = dt.replace(tzinfo=Timezone(found.get('timezone', '')))

            return dt

    raise ParseError()