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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 halt_running():
    '''Halts all running servers'''
    vultr = Vultr(API_KEY)

    try:
            serverList = vultr.server.list()
            #logging.info('Listing servers:\n%s', dumps(
            #serverList, indent=2
        #))
    except VultrError as ex:
        logging.error('VultrError: %s', ex)

    for serverID in serverList:
        if serverList[serverID]['power_status'] == 'running':
            logging.info(serverList[serverID]['label'] + " will be gracefully shutdown.")
            vultr.server.halt(serverID)