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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 purgeDatastream(self, pid, dsID, startDT=None, endDT=None, logMessage=None, force=False):
 """Purge a datastream, or specific versions of a dastream, from a Fedora object. On success, response content will include a list of timestamps for the purged datastream versions; on failure, response content may contain an error message. :param pid: object pid :param dsID: datastream ID :param startDT: optional start datetime (when purging specific versions) :param endDT: optional end datetime (when purging specific versions) :param logMessage: optional log message :rtype: :class:`requests.models.Response` """

        # /objects/{pid}/datastreams/{dsID} ? [startDT] [endDT] [logMessage] [force]
        http_args = {}
        if logMessage:
            http_args['logMessage'] = logMessage
        if startDT:
            http_args['startDT'] = startDT
        if endDT:
            http_args['endDT'] = endDT
        if force:
            http_args['force'] = force

        url = 'objects/%(pid)s/datastreams/%(dsid)s' % {'pid': pid, 'dsid': dsID}
        return self.delete(url, params=http_args)