def __intermediate_dns_servers(self, uci, address):
<EOL>if '<STR_LIT>' in uci:<EOL><INDENT>return uci['<STR_LIT>']<EOL><DEDENT>if address['<STR_LIT>'] in ['<STR_LIT>', '<STR_LIT>', '<STR_LIT:none>']:<EOL><INDENT>return None<EOL><DEDENT>dns = self.netjson.get('<STR_LIT>', None)<EOL>if dns:<EOL><INDENT>return '<STR_LIT:U+0020>'.join(dns)<EOL><DEDENT>
determines UCI interface "dns" option