db/storage/storage.go
func (s *Storage) Collection(name string) *Collection {
	return &Collection{Collection: s.session.DB(s.dbname).C(name)}
}
func (s *Storage) Collection(name string) *Collection {
	return &Collection{Collection: s.session.DB(s.dbname).C(name)}
}
// Collection returns a collection by its name.
//
// If the collection does not exist, MongoDB will create it.