OkHttpClient client = new OkHttpClient();
    EventSource.Factory factory = EventSource.Factory.create(client);
    server.enqueue(
      new MockResponse.Builder()
        .body("data: hello\n\n")
        .setHeader("content-type", "text/event-stream")
        .build()
    );
    Request request = new Request.Builder().url(server.url("/")).build();
    CompletableFuture<Void> future = new CompletableFuture<>();

});
```

### Text Processing and JSON
```java
import org.codelibs.core.text.*;

// JSON utilities with proper escaping
String escaped = JsonUtil.escape("Hello \"World\" with special chars");
String unescaped = JsonUtil.unescape(escaped);

// Text tokenization
Tokenizer tokenizer = new Tokenizer("field1,field2,field3", ",");
while (tokenizer.hasMoreTokens()) {

            }
        } catch (final Exception e) {
            logger.warn("Failed to create {} mapping.", configIndex, e);
        }
    }

    /**
     * Waits for the search engine cluster to reach yellow or green status.
     *
     * @param fessConfig the Fess configuration
     * @throws ContainerInitFailureException if the cluster doesn't become available
     */