How to use the multileveldown.server function in multileveldown

encode.updates({mainLayer: that.mainLayer, changes: that.changes})

          decode.adds(function (req, cb) {
            log.add(req.links, req.value, req.options, function (err, result) {
              encode.adds({
                id: req.id,
                error: err && err.message,
                notFound: err && err.notFound,
                value: result
              })
            })
            cb()
          })

          if (sock.unref) sock.unref()
          multileveldown.server(db, {encode: encode, decode: decode})
          pump(sock, stream, sock)
        })

var server = net.createServer((sock) => {
        sock.on('error', () => {
          sock.destroy()
        })

        sock.pipe(multileveldown.server(db)).pipe(sock)
      })

var server = net.createServer(function (sock) {
            if (sock.unref) sock.unref()
            sockets.push(sock)
            pump(sock, multileveldown.server(db), sock, function () {
              sockets.splice(sockets.indexOf(sock), 1)
            })
          })