Returns an immutable instance of [BillingListResponse].
public BillingListResponse build()Returns an immutable instance of [BillingListResponse]. Further updates to this [Builder] will not mutate the returned instance. The following fields are required:
.config()
.connectedToMetronome()
.connectedToStripe()
.displayName()
.isPersonal()IllegalStateException: if any required field is unset.