Openlayers 4 - get all child layers in a layer group

Question

How can I get all child layers of a given layer group in Openlayers?

I go as far as establishing that a given layer is in fact a group, but then I get stumped:

// Handle visibility control
$('i').on('click', function() {
    var layername = $(this).closest('li').data('layerid');
    var layer = findBy(map.getLayerGroup(), 'name', layername);
    var flagGroup = layer instanceof ol.layer.Group;
    if (flagGroup) {
       ...
    }
});

Answer 1

childLayers = layer.getLayers()

https://openlayers.org/en/latest/apidoc/ol.layer.Group.html#getLayers

Answer 2

Following up on Marc's answer, this is how implemented it:

// Handle visibility control
$('i').on('click', function() {
    var layername = $(this).closest('li').data('layerid');
    var layer = findBy(map.getLayerGroup(), 'name', layername);
    var flagGroup = layer instanceof ol.layer.Group;
    if (flagGroup) {
       var childLayerArray = layer.getLayers();
       childLayerArray.forEach(function (childLayer) { myFunction(childLayer);});
    }
});

function myFunction(childIn) {
     console.log("Child Layer is named: "+childIn.get('name'));
}

function findBy(layer, key, value) {

    if (layer.get(key) === value) {
        return layer;
    }

    // Find recursively if it is a group
    if (layer.getLayers) {
        var layers = layer.getLayers().getArray(),
                len = layers.length, result;
        for (var i = 0; i < len; i++) {
            result = findBy(layers[i], key, value);
            if (result) {
                return result;
            }
        }
    }

    return null;
}