}
    }

    public void addShutdownHook(final Runnable hook) {
        shutdownHookList.add(hook);
    }

    public String getHostname() {
        final Map<String, String> env = getEnvMap();
        if (env.containsKey("COMPUTERNAME")) {
            return env.get("COMPUTERNAME");
        }
        if (env.containsKey("HOSTNAME")) {
            return env.get("HOSTNAME");
        }

        private final Map<String, String> envVarMap;

        TestEnvVarSource(Map<String, String> envVarMap) {
            this.envVarMap = envVarMap;
        }

        public Map<String, String> getEnvMap() {
            return envVarMap;
        }
    }