* Sitemap were changed. The value for the lastmod tag should be in W3C
     * Datetime format.
     *
     * By providing the last modification timestamp, you enable search engine
     * crawlers to retrieve only a subset of the Sitemaps in the index i.e. a
     * crawler may only retrieve Sitemaps that were modified since a certain

import java.util.ArrayList;
import java.util.List;

/**
 * The NormalizerChain class implements the Normalizer interface and allows chaining multiple normalizers together.
 * It applies each normalizer in the order they were added to the chain.
 *
 * <p>Usage example:</p>
 * <pre>
 * NormalizerChain chain = new NormalizerChain();
 * chain.add(new SomeNormalizer());
 * chain.add(new AnotherNormalizer());

        sitemapsLocal.set(sitemaps);
    }

    /**
     * Removes sitemaps from the thread-local storage and returns them.
     * @return An array of sitemap URLs, or null if none were present.
     */
    public String[] removeSitemaps() {
        final String[] sitemaps = sitemapsLocal.get();
        if (sitemaps != null) {
            sitemapsLocal.remove();
        }