code: function startListening() {
      if (shouldBind) {
        try {
          bind(self.fd, self.port, self.host);
          listen(self.fd, self.options.backlog);
        } catch(e) {
          self.kill('SIGKILL');
          throw e;
        }
      }
      self.callback && self.callback();
      self.emit('listening');
    }
docs: bind / listen