@Test
    public void testConcatKinds() {
        // Test static concatKinds method
        SuggestItem.Kind[] kinds1 = { SuggestItem.Kind.QUERY };
        SuggestItem.Kind[] kinds2 = { SuggestItem.Kind.DOCUMENT, SuggestItem.Kind.QUERY };

        SuggestItem.Kind[] result = SuggestItem.concatKinds(kinds1, kinds2);

        assertNotNull(result);
        assertEquals(2, result.length); // Should not have duplicates

        boolQueryBuilder.must(QueryBuilders.termQuery(FieldNames.KINDS, SuggestItem.Kind.DOCUMENT.toString()));
        boolQueryBuilder.mustNot(QueryBuilders.termQuery(FieldNames.KINDS, SuggestItem.Kind.QUERY.toString()));
        boolQueryBuilder.mustNot(QueryBuilders.termQuery(FieldNames.KINDS, SuggestItem.Kind.USER.toString()));

### SuggestItem (Domain Entity)
Location: `src/main/java/org/codelibs/fess/suggest/entity/SuggestItem.java`

Core attributes: `text`, `timestamp`, `queryFreq`, `docFreq`, `userBoost`, `readings`, `tags`, `roles`, `languages`, `kinds`

Kind types: `DOCUMENT`, `QUERY`, `USER`

---

## Development Workflow

### Build Commands

```bash
mvn compile                              # Compile

        }
        return deleteWordsByKind(FieldNames.QUERY_FREQ, SuggestItem.Kind.QUERY, item -> item.setQueryFreq(0), SuggestItem.Kind.DOCUMENT,
                SuggestItem.Kind.USER);
    }

    /**
     * Common method to delete words by kind.
     * @param freqField The frequency field name.
     * @param kindToRemove The kind to remove.
     * @param freqSetter The consumer to set frequency to 0.

        // Check kind
        assertNotNull(suggestItem.getKinds());
        // The kinds array structure might be different
        boolean hasUserKind = false;
        for (SuggestItem.Kind kind : suggestItem.getKinds()) {
            if (kind == SuggestItem.Kind.USER) {
                hasUserKind = true;
                break;
            }
        }

        secondLine.put("score", (item.getQueryFreq() + item.getDocFreq()) * item.getUserBoost());
        secondLine.put("tags", item.getTags());
        secondLine.put("roles", item.getRoles());
        secondLine.put("kinds", Arrays.toString(item.getKinds()));
        secondLine.put("@timestamp", item.getTimestamp());

        try (OutputStream out1 = getXContentOutputStream(firstLineMap); OutputStream out2 = getXContentOutputStream(secondLine)) {

      checkState(
          this.maximumSize == UNSET_INT,
          "weigher can not be combined with maximum size (%s provided)",
          this.maximumSize);
    }

    // safely limiting the kinds of caches this can produce
    @SuppressWarnings("unchecked")
    CacheBuilder<K1, V1> me = (CacheBuilder<K1, V1>) this;
    me.weigher = checkNotNull(weigher);
    return me;
  }

  long getMaximumWeight() {

 * is not an open, stateful stream for input that can be read and closed. Instead, it is an
 * immutable <i>supplier</i> of {@code InputStream} instances.
 *
 * <p>{@code ByteSource} provides two kinds of methods:
 *
 * <ul>
 *   <li><b>Methods that return a stream:</b> These methods should return a <i>new</i>, independent
 *       instance each time they are called. The caller is responsible for ensuring that the

 * CharSource} is not an open, stateful stream of characters that can be read and closed. Instead,
 * it is an immutable <i>supplier</i> of {@code Reader} instances.
 *
 * <p>{@code CharSource} provides two kinds of methods:
 *
 * <ul>
 *   <li><b>Methods that return a reader:</b> These methods should return a <i>new</i>, independent
 *       instance each time they are called. The caller is responsible for ensuring that the

 * CharSource} is not an open, stateful stream of characters that can be read and closed. Instead,
 * it is an immutable <i>supplier</i> of {@code Reader} instances.
 *
 * <p>{@code CharSource} provides two kinds of methods:
 *
 * <ul>
 *   <li><b>Methods that return a reader:</b> These methods should return a <i>new</i>, independent
 *       instance each time they are called. The caller is responsible for ensuring that the