assertTrue("Content should end with }", contentNew.trim().endsWith("}"));
        assertTrue("Content should be substantial", contentNew.length() > 100);

        // Verify it contains expected mapping fields
        assertTrue("Should contain properties definition", contentNew.contains("properties"));
    }

    /**

During crawling and indexing, Fess:

1. Detects language from document content using Apache Tika
2. Validates against `supported.languages` list
3. Creates language-specific fields (e.g., `content_ja`, `title_en`, `content_sv`)
4. Applies language-specific analyzers for better search results

Configured in `fess_config.properties`:
```properties
indexer.language.fields=content,important_content,title
```

        assertEquals(threadCount * operationsPerThread, successCount.get());
        assertTrue(overallTimeMs < 1000, "Operations should complete quickly without lock contention");

        pool.close();
    }

    /**
     * Test buffer cache performance with concurrent operations
     */
    @Test
    public void testBufferCachePerformance() throws Exception {

        // Test with Japanese characters
        String word = "日本語テスト";
        float boost = 2.0f;
        List<String> readings = Arrays.asList("ニホンゴテスト");
        List<String> fields = Arrays.asList("content_ja");
        List<String> tags = Arrays.asList("japanese");
        List<String> roles = Arrays.asList("admin");

        elevateWord = new ElevateWord(word, boost, readings, fields, tags, roles);

- Lease entries should be evicted based on LRU when max leases reached
- Implement periodic cleanup of expired leases

### 9.2 Thread Safety
- Use concurrent data structures for lease storage
- Minimize lock contention in hot paths
- Async handling of lease breaks

### 9.3 Network Efficiency
- Batch lease requests when possible
- Implement lease key reuse for related files
- Optimize lease break acknowledgment timing