long before = countTmpFiles();
        logger.info("Before request. Number of temp files: " + before);
        req.execute(res -> {
            logger.info("Processing request. Number of temp files: " + countTmpFiles());
        }, e -> {});
        long after = countTmpFiles();
        logger.info("After close response. Number of temp files: " + after);

        // ## Assert ##
        assertEquals(before, after);
    }

import java.io.ByteArrayInputStream;
import java.io.Closeable;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.util.logging.Logger;

public class ContentCache implements Closeable {

    protected static final Logger logger = Logger.getLogger(ContentCache.class.getName());

    private final byte[] data;

 * governing permissions and limitations under the License.
 */
package org.codelibs.curl.io;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.util.logging.Logger;

import org.apache.commons.io.output.DeferredFileOutputStream;

public class ContentOutputStream extends DeferredFileOutputStream {

      (a) You must give any other recipients of the Work or
          Derivative Works a copy of this License; and

      (b) You must cause any modified files to carry prominent notices
          stating that You changed the files; and

      (c) You must retain, in the Source form of any Derivative Works
          that You distribute, all copyright, patent, trademark, and