code: func (e *DefaultEndorsement) Init(dependencies ...Dependency) error {
  	for _, dep := range dependencies {
  		sIDFetcher, isSigningIdentityFetcher := dep.(SigningIdentityFetcher)
  		if !isSigningIdentityFetcher {
  			continue
  		}
  		e.SigningIdentityFetcher = sIDFetcher
  		return nil
  	}
  	return errors.New("could not find SigningIdentityFetcher in dependencies")
  }
docs: // Init injects dependencies into the instance of the Plugin