public Array getArray(String name) {
        Array a = arrayMap.get(name);
        if (a == null) {
            validateArray(name);
            a = new Array(configDefinition, name);
            arrayMap.put(name, a);
        }
        return a;
    }
Create a new array where new values may be added.

@param name Name of array.
@return Array object supporting adding elements to it.
config/src/main/java/com/yahoo/vespa/config/ConfigPayloadBuilder.java