Wrapper of __get_hosts_filename but create host file if it
    does not exist.

def _get_or_create_hostfile():
    '''
    Wrapper of __get_hosts_filename but create host file if it
    does not exist.
    '''
    hfn = __get_hosts_filename()
    if hfn is None:
        hfn = ''
    if not os.path.exists(hfn):
        with salt.utils.files.fopen(hfn, 'w'):
            pass
    return hfn