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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 _render(roster_file, **kwargs):
 """ Render the roster file """

    renderers = salt.loader.render(__opts__, {})
    domain = __opts__.get('roster_domain', '')
    try:
        result = salt.template.compile_template(roster_file,
                                                renderers,
                                                __opts__['renderer'],
                                                __opts__['renderer_blacklist'],
                                                __opts__['renderer_whitelist'],
                                                mask_value='passw*',
                                                **kwargs)
        result.setdefault('host', '{}.{}'.format(os.path.basename(roster_file), domain))
        return result
    except:  # pylint: disable=W0702
        log.warning('Unable to render roster file "%s".', roster_file, exc_info=True)
        return {}