*
     * @return true if valid, false if invalidated
     */
    public boolean isValid() {
        return valid;
    }

    /**
     * Invalidate this memory region
     *
     * After invalidation, the region cannot be used for RDMA operations.
     */
    public abstract void invalidate();

    /**
     * Generate local key for this memory region
     *

    List<Object> invalidated = new ArrayList<>();
    Cache<Integer, Integer> cache =
        new AbstractCache<Integer, Integer>() {
          @Override
          public Integer getIfPresent(Object key) {
            throw new UnsupportedOperationException();
          }

          @Override
          public void invalidate(Object key) {
            invalidated.add(key);
          }
        };

        }
        buf.readOctetArray(contextHandle, 0, 20);
    }

    /**
     * Checks if the context handle has been invalidated (all zeros).
     * A successful unregistration typically results in a zeroed context handle.
     *
     * @return true if the context handle has been invalidated
     */
    public boolean isContextHandleInvalidated() {
        if (contextHandle == null) {
            return true;

   *
   * <p>If {@code node} is removed from the graph after this method is called, the {@code Set}
   * {@code view} returned by this method will be invalidated, and will throw {@code
   * IllegalStateException} if it is accessed in any way, with the following exceptions:
   *
   * <ul>
   *   <li>{@code view.equals(view)} evaluates to {@code true} (but any other {@code equals(...)}

   *
   * <p>If {@code node} is removed from the graph after this method is called, the {@code Set}
   * {@code view} returned by this method will be invalidated, and will throw {@code
   * IllegalStateException} if it is accessed in any way, with the following exceptions:
   *
   * <ul>
   *   <li>{@code view.equals(view)} evaluates to {@code true} (but any other {@code equals()}

        // Simulate file addition
        directoryLeaseManager.handleDirectoryChange(directoryPath, "newfile.txt", DirectoryChangeNotifier.DirectoryChangeType.FILE_ADDED);

        // Cache should be invalidated
        assertFalse(cacheEntry.isComplete());

        // Step 9: Test lease break
        // Re-populate cache
        directoryLeaseManager.updateDirectoryCache(directoryPath, files);

   *
   * <p>If {@code node} is removed from the network after this method is called, the {@code Set}
   * {@code view} returned by this method will be invalidated, and will throw {@code
   * IllegalStateException} if it is accessed in any way, with the following exceptions:
   *
   * <ul>
   *   <li>{@code view.equals(view)} evaluates to {@code true} (but any other {@code equals()}

   *
   * <p>If {@code node} is removed from the graph after this method is called, the {@code Set}
   * {@code view} returned by this method will be invalidated, and will throw {@code
   * IllegalStateException} if it is accessed in any way, with the following exceptions:
   *
   * <ul>
   *   <li>{@code view.equals(view)} evaluates to {@code true} (but any other {@code equals()}

   *
   * <p>If {@code node} is removed from the graph after this method is called, the {@code Set}
   * {@code view} returned by this method will be invalidated, and will throw {@code
   * IllegalStateException} if it is accessed in any way, with the following exceptions:
   *
   * <ul>
   *   <li>{@code view.equals(view)} evaluates to {@code true} (but any other {@code equals()}

    }

    /**
     * Repositions this stream to the position at the time the mark method was last called.
     *
     * @throws IOException if this stream has not been marked or if the mark has been invalidated
     */
    @Override
    public synchronized void reset() throws IOException {
        inputStream.reset();
    }

    /**
     * Skips over and discards n bytes of data from this input stream.