// Lookup Env var.
	value = env.Get(envVar, "")
	if value != "" {
		cs = ValueSourceEnv
		return value, cs, isRedacted
	}

	// Lookup config store.
	if subSysStore, ok := c[subSys]; ok {
		if kvs, ok2 := subSysStore[target]; ok2 {
			var ok3 bool
			value, ok3 = kvs.Lookup(cfgParam)
			if ok3 {
				cs = ValueSourceCfg
				return value, cs, isRedacted
			}
		}
	}