Custom attributes can be created by creating a map that contains all the key and value pairs as follows:
HashMap map = new HashMap<String, Object>();
map.put("email", "[email protected]");
map.put("name", "VWO Insights");
VWOInsights.INSTANCE.sendCustomAttribute(map);
val map = mutableMapOf<String, Any>()
map["email"] = "[email protected]"
map["name"] = "VWO Insights"
VWOInsights.sendCustomAttribute(map)