Calling this.serverless.variables.populateService with the new variablesResolutionMode: 20210326

Hey everybody, when writing a plugin, I’ve read where this.serverless.variables.populateService (see this link) calls the old variable resolver. However, I cannot find any information on how to populate the service with the new variable resolver (i.e. variablesResolutionMode: 20210326). Can anybody point me in the right direction?