in lib/template/pattern/lambda-construct.ts [99:110]
private loadLayers(lambdaName: string, layerArns: string[]): any[] {
var layers = [];
if (layerArns != undefined && layerArns.length > 0) {
for (var arn of layerArns) {
let list: string[] = arn.split(':');
layers.push(lambda.LayerVersion.fromLayerVersionArn(this, `${lambdaName}-${list[list.length - 2]}-layer`, arn))
}
}
return layers;
}