// architecture: Database
type DB interface {
	Query() string
}

// architecture: Service
type Users struct {
	db       *DB
	comments *Comments
}

// architecture: Service
type Comments struct {
	db    *DB
	users *Users
}

// architecture: Server
type Server struct {
	comments *Comments
	users    *Users
}

// we can create links between interfaces and implementations with idiomatic Go
var _ DB = &PostgresDB{}
var _ DB = (*SqliteDB)(nil)

// architecture: Database Implementation
type PostgresDB struct{}

// architecture: Database Implementation
type SqliteDB struct{}

archview ./... | dot -Tsvg > graph.svg

archview -out example.graphml ./... 

go get -u github.com/storj/archview

archview [-format (dot|dot-basic|graphml)] [-out <output file>] [packages]