Connection pool

By default this provider uses single client to server connection to FCM for sending notifications. If in your use case it is to small (as you need better performance), you should adjust value of pool-size configuration property. Setting it to 5 will open five connections to FCM for better performance.

Example. 

push () {
    'fcm-xmpp-api' () {
        'pool-size' = 5
    }
}