* loader and prevent it from being garbage collected. This poses a problem for environments where
 * you want to throw away the class loader. For example, dynamically reloading a web application or
 * unloading an OSGi bundle.
 *
 * <p>{@code com.google.common.base.FinalizableReferenceQueue} loads this class in its own class
 * loader. That way, this class doesn't prevent the main class loader from getting garbage

    @Nullable V get();

    /**
     * Waits for a value that may still be loading. Unlike get(), this method can block (in the case
     * of FutureValueReference).
     *
     * @throws ExecutionException if the loading thread throws an exception
     * @throws ExecutionError if the loading thread throws an error
     */
    V waitForValue() throws ExecutionException;

    @Nullable V get();

    /**
     * Waits for a value that may still be loading. Unlike get(), this method can block (in the case
     * of FutureValueReference).
     *
     * @throws ExecutionException if the loading thread throws an exception
     * @throws ExecutionError if the loading thread throws an error
     */
    V waitForValue() throws ExecutionException;

    @Override
    public @Nullable Class<?> loadFinalizer() {
      if (disabled) {
        return null;
      }
      if (isAndroid()) {
        // We need not worry about class unloading under Android. Plus, this approach wouldn't work.
        return null;
      }
      ClassLoader systemLoader;
      try {
        systemLoader = ClassLoader.getSystemClassLoader();

    @Override
    public @Nullable Class<?> loadFinalizer() {
      if (disabled) {
        return null;
      }
      if (isAndroid()) {
        // We need not worry about class unloading under Android. Plus, this approach wouldn't work.
        return null;
      }
      ClassLoader systemLoader;
      try {
        systemLoader = ClassLoader.getSystemClassLoader();

                    // ignore
                }
            }
        }
        lastModified = propertiesFile.lastModified();
    }

    /**
     * Returns the current properties, reloading them if the file has been updated.
     *
     * @return The current {@link Properties} instance.
     */
    protected Properties getProperties() {
        if (isUpdated()) {
            load();
        }

 * It includes functionality for updating configurations in a separate thread and controlling the reloading interval.
 */
public abstract class AbstractConfigHelper {

    /**
     * Default constructor.
     */
    public AbstractConfigHelper() {
        // Default constructor
    }

    /**
     * The interval for reloading.
     */
    protected long reloadInterval = 1000L;

    /**

  /**
   * Returns the value associated with {@code key} in this cache, first loading that value if
   * necessary. No observable state associated with this cache is modified until loading completes.
   *
   * <p>If another call to {@link #get} or {@link #getUnchecked} is currently loading the value for
   * {@code key}, simply waits for that thread to finish and returns its loaded value. Note that

  /**
   * Returns the value associated with {@code key} in this cache, first loading that value if
   * necessary. No observable state associated with this cache is modified until loading completes.
   *
   * <p>If another call to {@link #get} or {@link #getUnchecked} is currently loading the value for
   * {@code key}, simply waits for that thread to finish and returns its loaded value. Note that

 *       <ul>
 *         <li>After successfully loading an entry {@code missCount} and {@code loadSuccessCount}
 *             are incremented, and the total loading time, in nanoseconds, is added to {@code
 *             totalLoadTime}.
 *         <li>When an exception is thrown while loading an entry, {@code missCount} and {@code
 *             loadExceptionCount} are incremented, and the total loading time, in nanoseconds, is