func Level(level string) Option {
	return func(concern *ReadConcern) {
		concern.level = level
	}
}
Level creates an option that sets the level of a ReadConcern.
package readconcern  
import (
	"go.mongodb.org/mongo-driver/bson/bsontype"
	"go.mongodb.org/mongo-driver/x/bsonx/bsoncore"
)
type ReadConcern struct {
	level string
}
type Option func(concern *ReadConcern)