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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 set_bpf_filter_on_all_devices(filterstr):
        '''
        Long method name, but self-explanatory.  Set the bpf
        filter on all devices that have been opened.
        '''
        with PcapLiveDevice._lock:
            for dev in PcapLiveDevice._OpenDevices.values():
                _PcapFfi.instance()._set_filter(dev, filterstr)