delegates property Null safety
The sequence of service accounts in a delegation chain.
Each service account must be granted the
roles/iam.serviceAccountTokenCreator role on its next service account in
the chain. The last service account in the chain must be granted the
roles/iam.serviceAccountTokenCreator role on the service account that is
specified in the
name field of the request. The delegates must have the
character is required; replacing it with a project ID is invalid.