private double average(List<Long> data) {
        return data.stream()
                .mapToDouble(Double::valueOf)
                .map(dataPoint -> dataPoint / data.size())
                .sum();
    }
test that the continued creation of proxy classes does not
constantly consume memory.
jgiven-core/src/test/java/com/tngtech/jgiven/impl/ProxyClassPerformanceTest.java