import java.util.Collection;
import java.util.Map;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link Multimap} using hash tables.
 *
 * <p>The multimap does not store duplicate key-value pairs. Adding a new key-value pair equal to an
 * existing key-value pair has no effect.
 *
 * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
 * views are modifiable.

        // Test unregistration
        assertTrue(mockService.unregisterWitness(regId));
        assertEquals(0, mockService.getRegistrationCount());
        assertFalse(mockService.hasRegistration(regId));

        // Test duplicate unregistration
        assertFalse(mockService.unregisterWitness(regId));
    }

    @Test
    void testMockServiceNotifications() {
        // Test notification sending (just logs for mock)

    checkNotNull(mergeFunction, "mergeFunction");

    /*
     * No mutable Table exactly matches the insertion order behavior of ImmutableTable.Builder, but
     * the Builder can't efficiently support merging of duplicate values.  Getting around this
     * requires some work.
     */

    return Collector.of(
        ImmutableTableCollectorState<R, C, V>::new,
        (state, input) ->
            state.put(

   * referencing the type variables seem worthwhile.
   */
  final void checkNoDuplicate(R rowKey, C columnKey, @Nullable V existingValue, V newValue) {
    checkArgument(
        existingValue == null,
        "Duplicate key: (row=%s, column=%s), values: [%s, %s].",
        rowKey,
        columnKey,
        newValue,
        existingValue);
  }

  // redeclare to satisfy our test for b/310253115
  @Override

        try {
            // For TCP fallback, simulate writing data through the TCP socket
            int bytesToWrite = Math.min(length, buffer.remaining());

            ByteBuffer writeBuffer = buffer.duplicate();
            writeBuffer.limit(writeBuffer.position() + bytesToWrite);

            int totalWritten = 0;
            while (writeBuffer.hasRemaining()) {

    /**
     * Calculates the effective repositories for the given input repositories which are assumed to be already mirrored
     * (if applicable). This process will essentially remove duplicate repositories by merging them into one equivalent
     * repository. It is worth to point out that merging does not simply choose one of the input repositories and

void RegisterTracingEngineFactory(const string& name, FactoryFunction factory) {
  assert((!GetFactories().count(name)) ||
         (GetFactories()[name] == factory) &&
             "Duplicate tracing factory registration");
  GetFactories()[name] = factory;
}

absl::Status SetDefaultTracingEngine(const char* name) {
  auto entry = GetFactories().find(name);
  if (entry != GetFactories().end()) {

 *
 * <p>When iterating through the collections supplied by this class, the ordering of values for a
 * given key agrees with the order in which the values were added.
 *
 * <p>This multimap allows duplicate key-value pairs. After adding a new key-value pair equal to an
 * existing key-value pair, the {@code ArrayListMultimap} will contain entries for both the new
 * value and the old value.
 *

- **StorageClient**: MinIO SDK, `storage://bucket/path`

### Services

- **UrlQueueService**: URL queue management (FIFO), duplicate detection
- **DataService**: Access result persistence, iteration
- Implementations: `UrlQueueServiceImpl`, `DataServiceImpl` (in-memory), `OpenSearchDataService` (persistent)

### Processing Pipeline

```

      for (Object o : entries) {
        @SuppressWarnings("unchecked")
        Multiset.Entry<E> entry = (Entry<E>) o;
        checkArgument(
            elements.add(entry.getElement()), "Duplicate keys not allowed in EntrySetGenerator");
        for (int i = 0; i < entry.getCount(); i++) {
          contents.add(entry.getElement());
        }
      }