K oldKey = delegate.key;
            int keyHash = smearedHash(key);
            if (keyHash == delegate.keyHash && Objects.equal(key, oldKey)) {
              return key;
            }
            checkArgument(seekByKey(key, keyHash) == null, "value already present: %s", key);
            delete(delegate);
            BiEntry<K, V> newEntry =
                new BiEntry<>(key, keyHash, delegate.value, delegate.valueHash);

        return oldKey;
      }
    }

    int predecessor = lastInInsertionOrder;
    int keyHash = Hashing.smearedHash(key);
    int keyEntry = findEntryByKey(key, keyHash);
    if (force) {
      if (keyEntry != ABSENT) {
        predecessor = prevInInsertionOrder[keyEntry];
        removeEntryKeyHashKnown(keyEntry, keyHash);
      }
    } else {
      checkArgument(keyEntry == ABSENT, "Key already present: %s", key);

		var keyHash string
		{
			key := eventData.S3.Bucket.Name + "/" + objectName
			if target.client.isAtleastV7() {
				hh, _ := highwayhash.New(magicHighwayHash256Key) // New will never return error since key is 256 bit
				hh.Write([]byte(key))
				hashBytes := hh.Sum(nil)
				keyHash = base64.URLEncoding.EncodeToString(hashBytes)
			} else {
				keyHash = key
			}
		}

      Entry<K, V> entry = requireNonNull(entryArray[i]);
      K key = entry.getKey();
      V value = entry.getValue();
      checkEntryNotNull(key, value);
      int keyHash = key.hashCode();
      int valueHash = value.hashCode();
      int keyBucket = Hashing.smear(keyHash) & mask;
      int valueBucket = Hashing.smear(valueHash) & mask;

      ImmutableMapEntry<K, V> nextInKeyBucket = keyTable[keyBucket];

	}
	return err
}

func (ies *IAMEtcdStore) watch(ctx context.Context, keyPath string) <-chan iamWatchEvent {
	ch := make(chan iamWatchEvent)

	// go routine to read events from the etcd watch channel and send them
	// down `ch`
	go func() {
		for {
		outerLoop:
			watchCh := ies.client.Watch(ctx,
				keyPath, etcd.WithPrefix(), etcd.WithKeysOnly())

			for {
				select {
				case <-ctx.Done():

}

// TableExpression represents the FROM clause
type TableExpression struct {
	Table *JSONPath `parser:"@@"`
	As    string    `parser:"( \"AS\"? @Ident )?"`
}

// JSONPathElement represents a keypath component
type JSONPathElement struct {
	Key            *ObjectKey `parser:"  @@"`               // ['name'] and .name forms
	Index          *int       `parser:"| \"[\" @Int \"]\""` // [3] form

)

const (
	mysqlTableExists = `SELECT 1 FROM %s;`
	// Some MySQL has a 3072 byte limit on key sizes.
	mysqlCreateNamespaceTable = `CREATE TABLE %s (
             key_name VARCHAR(3072) NOT NULL,
             key_hash CHAR(64) GENERATED ALWAYS AS (SHA2(key_name, 256)) STORED NOT NULL PRIMARY KEY,
             value JSON)
           CHARACTER SET = utf8mb4 COLLATE = utf8mb4_bin ROW_FORMAT = Dynamic;`