You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: roles.go
    path of file: ./repos/photoprism/internal/acl
    
    the code of the file until where you have to start completion: package acl

// Roles that can be assigned to users.
const (
	RoleDefault Role = "default"
	RoleAdmin   Role = "admi
    
func (roles Roles) Allow(role Role, grant Permission) bool {
	if a, ok := roles[role]; ok {
		return a.Allow(grant)
	} else if a, ok = roles[RoleDefault]; ok {
		return a.Allow(grant)
	}

	return false
}