30   const server = net.createServer();  constant
32   server.on('error', common.mustNotCall());
34   server
36       const address4 = server.address();
40       server.close();
56   const server = net.createServer();  constant
58   server.on('error', common.mustNotCall());
60   server.listen(common.PORT + 2, localhost, common.mustCall(() => {
61     const address = server.address();
65     server.close();
71   const server = net.createServer();  constant
73   server.on('error', common.mustNotCall());
76   server.listen(common.PORT + 3, common.mustCall(() => {
77     const address = server.address();
81     server.close();
87   const server = net.createServer();  constant
89   server.on('error', common.mustNotCall());
92   server.listen(common.mustCall(() => {
93     const address = server.address();
96     server.close();
102   const server = net.createServer();  constant
104   server.on('error', common.mustNotCall());
107   server.listen(0, common.mustCall(() => {
108     const address = server.address();
111     server.close();