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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 is_crm_dc():
 """ Determine leadership by querying the pacemaker Designated Controller """

    cmd = ['crm', 'status']
    try:
        status = subprocess.check_output(cmd, stderr=subprocess.STDOUT)
        if not isinstance(status, six.text_type):
            status = six.text_type(status, "utf-8")
    except subprocess.CalledProcessError as ex:
        raise CRMDCNotFound(str(ex))

    current_dc = ''
    for line in status.split('\n'):
        if line.startswith('Current DC'):
            # Current DC: juju-lytrusty-machine-2 (168108163) - partition with quorum
            current_dc = line.split(':')[1].split()[0]
    if current_dc == get_unit_hostname():
        return True
    elif current_dc == 'NONE':
        raise CRMDCNotFound('Current DC: NONE')

    return False