@Nullable
    private static <T> T getAndParse(String name, Function<String, T> parser) {
        final String val = getNormalized(name);
        if (val == null) {
            return null;
        }
        return parser.apply(val);
    }
Implementation of {@link FlagsProvider} which provides values from JVM options to {@link Flags}.
core/src/main/java/com/linecorp/armeria/common/SystemPropertyFlagsProvider.java