@Nullable
    private static String sanitize(
            BiFunction<? super RequestContext, String,
                    ? extends @Nullable Object> contentSanitizer,
            RequestContext ctx, String produced) {
        final Object sanitized = contentSanitizer.apply(ctx, produced);
        return sanitized != null ? sanitized.toString() : "<sanitized>";
    }
Sets up the response {@link ContentPreviewer} to set
{@link RequestLogBuilder#responseContentPreview(String)} when the preview is available.
core/src/main/java/com/linecorp/armeria/internal/logging/ContentPreviewingUtil.java