*   <li>{@code done} - Flag indicating whether the file has been retrieved.</li>
 * </ul>
 *
 * <p>Constructors:</p>
 * <ul>
 *   <li>{@code ContentOutputStream(int threshold, File tmpDir)} - Constructs a ContentOutputStream with a specified threshold and temporary directory.</li>
 * </ul>
 *
 * <p>Methods:</p>
 * <ul>
 *   <li>{@code getFile()} - Marks the file as retrieved and returns the file.</li>

- `org.codelibs.curl.CurlResponse`: wrapper for HTTP responses.
- `org.codelibs.curl.CurlException`: unchecked exception for errors.
- `org.codelibs.curl.io.ContentCache` and `ContentOutputStream`: internal utilities for streaming and caching.

Refer to the Javadoc for full API details.

## Building and Testing

```bash
git clone https://github.com/codelibs/curl4j.git
cd curl4j
mvn clean test

│   │   ├── CurlException.java     # Unchecked exception for HTTP errors
│   │   └── io/
│   │       ├── ContentCache.java       # In-memory or file-based caching
│   │       └── ContentOutputStream.java # Threshold-based output stream
│   └── test/java/org/codelibs/curl/
│       ├── CurlTest.java          # Factory method tests
│       ├── CurlRequestTest.java   # Request builder tests