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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 get_execution_host_info():
 """ Tries to return a tuple describing the execution host. Doesn't work for all queueing systems Returns: (HOSTNAME, CLUSTER_NAME) """

    host = os.environ.get('HOSTNAME', None)
    cluster = os.environ.get('SGE_O_HOST', None)
    if host is None:
        try:
            import socket
            host = host or socket.gethostname()
        except:
            pass
    return host or 'unknown', cluster or 'unknown'