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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 enable_site(site_name):
 """Enable an available Nginx site."""


    site_available = u'/etc/nginx/sites-available/%s' % site_name
    site_enabled = u'/etc/nginx/sites-enabled/%s' % site_name
    if files.exists(site_available):
        sudo(u'ln -s -f %s %s' % (site_available, site_enabled))
        restart_service(u'nginx')
    else:
        abort(u'%s site configuration is not available' % site_name)