infraʹґଘͤͣ͞ʹdomainͷinterfaceʹґଘͤ͞Δ policyRepo domain.PolicyRepository } func (p *Policy) Get(id string) (*model.Policy, error) { // ... res, err := p.policyRepo.Get(id) if err != nil { return nil, err } return res, nil } ``` ```go:domain/repository.go package domain // application͔Βݟ͑ΔॴʹinterfaceΛஔ͘ type PolicyRepository interface { Get(id string) (*model.Policy, error) } ```