│   ├── collection/     # Enhanced collection utilities
│   ├── convert/        # Type conversion utilities
│   ├── exception/      # Runtime exception wrappers
│   ├── io/            # I/O and resource management
│   ├── lang/          # Reflection and language utilities
│   ├── log/           # Logging abstraction
│   ├── text/          # Text processing utilities
│   ├── xml/           # XML processing utilities

import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.TimeoutException;
import org.jspecify.annotations.NullMarked;

/**
 * Testing utilities relating to garbage collection finalization.
 *
 * <p>Use this class to test code triggered by finalization, that is, one of the following
 * actions taken by the java garbage collection system:
 *
 * <ul>

 *       add overloads that accept start and end indexes.
 *   <li>Can be streamed without "breaking the chain": {@code foo.getBarLongs().stream()...}.
 *   <li>Access to all collection-based utilities via {@link #asList} (though at the cost of
 *       allocating garbage).
 * </ul>
 *
 * <p>Disadvantages compared to {@code long[]}:
 *
 * <ul>

 *       add overloads that accept start and end indexes.
 *   <li>Can be streamed without "breaking the chain": {@code foo.getBarInts().stream()...}.
 *   <li>Access to all collection-based utilities via {@link #asList} (though at the cost of
 *       allocating garbage).
 * </ul>
 *
 * <p>Disadvantages compared to {@code int[]}:
 *
 * <ul>

import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.TimeoutException;
import org.jspecify.annotations.NullMarked;

/**
 * Testing utilities relating to garbage collection finalization.
 *
 * <p>Use this class to test code triggered by finalization, that is, one of the following
 * actions taken by the java garbage collection system:
 *
 * <ul>

 * {@code String} and a {@code String} to an {@code int} that treat the {@code int} as an unsigned
 * number.
 *
 * <p>Users of these utilities must be <i>extremely careful</i> not to mix up signed and unsigned
 * {@code int} values. When possible, it is recommended that the {@link UnsignedInteger} wrapper

 * {@code String} and a {@code String} to a {@code long} that treat the {@code long} as an unsigned
 * number.
 *
 * <p>Users of these utilities must be <i>extremely careful</i> not to mix up signed and unsigned
 * {@code long} values. When possible, it is recommended that the {@link UnsignedLong} wrapper class

│   │   ├── contents/               # Content parsers and readers
│   │   └── writer/                 # Index writing strategies
│   ├── converter/                  # Text conversion utilities
│   ├── normalizer/                 # Text normalization
│   ├── analysis/                   # Custom analyzers
│   └── settings/                   # Configuration management
├── main/resources/

import java.util.LinkedHashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Queue;
import java.util.Set;
import org.jspecify.annotations.NullMarked;

/**
 * Utilities for collecting and validating tester requirements from annotations.
 *
 * @author George van den Driessche
 */
@GwtIncompatible
public final class FeatureUtil {

      assertThat(entrySet.retainAll(asList(null, entryOf(1, 1), entryOf(15, 15)))).isFalse();
      checkEmpty(entrySet);
      checkEmpty(cache);
    }
  }

  /* ---------------- Local utilities -------------- */

  /** Most of the tests in this class run against every one of these caches. */
  private Iterable<LoadingCache<Object, Object>> caches() {
    // lots of different ways to configure a LoadingCache