failed building example with vgo

[wxart]

go get -u golang.org/x/vgo && touch go.mod && vgo build

then got errors as follows:

./main.go:15:12: undefined: cluster.NewConfig
./main.go:22:38: not enough arguments in call to cluster.NewConsumer
./main.go:41:28: consumer.Notifications undefined (type *cluster.Consumer has no field or method Notifications)
./main.go:51:13: consumer.MarkOffset undefined (type *cluster.Consumer has no field or method MarkOffset)