It might also help avoid confusion for new developers that see an unused parameter in your code and could think it's unnecessary.

///

/// info

In this example we use invented custom headers `X-Key` and `X-Token`.

But in real cases, when implementing security, you would get more benefits from using the integrated [Security utilities (the next chapter)](../security/index.md){.internal-link target=_blank}.

///

import org.lastaflute.web.util.LaRequestUtil;

/**
 * Helper class for managing virtual host configurations and routing.
 * This class provides functionality to handle virtual host-based routing
 * and path resolution based on HTTP headers.
 */
public class VirtualHostHelper {

    /**
     * Default constructor.
     */
    public VirtualHostHelper() {
        // Default constructor
    }

    /**

      Request
        .Builder()
        .url(server.url("/"))
        .build()

    // No extra headers in the application's request.
    assertThat(request.header("User-Agent")).isNull()
    assertThat(request.header("Host")).isNull()
    assertThat(request.header("Accept-Encoding")).isNull()

    // No extra headers in the application's response.
    val response = client.newCall(request).execute()

}

// readGNUSparsePAXHeaders checks the PAX headers for GNU sparse headers.
// If they are found, then this function reads the sparse map and returns it.
// This assumes that 0.0 headers have already been converted to 0.1 headers
// by the PAX header parsing logic.
func (tr *Reader) readGNUSparsePAXHeaders(hdr *Header) (sparseDatas, error) {
	// Identify the version of GNU headers.
	var is1x0 bool

        try (ResponseBody responseBody = response.body()) {
          if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

          Headers responseHeaders = response.headers();
          for (int i = 0, size = responseHeaders.size(); i < size; i++) {
            System.out.println(responseHeaders.name(i) + ": " + responseHeaders.value(i));
          }

        private String queryString;
        private String servletPath;
        private String method = "GET";
        private String requestURI = "/";
        private final Map<String, String> headers = new java.util.HashMap<>();

        public void setQueryString(String queryString) {
            this.queryString = queryString;
        }

        public void setServletPath(String servletPath) {

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package okhttp3.internal.http

import java.io.IOException
import okhttp3.Headers
import okhttp3.Request
import okhttp3.Response
import okhttp3.Route
import okhttp3.internal.connection.RealCall
import okio.Sink
import okio.Socket
import okio.Source

    }

    val recorded = server.takeRequest()
    assertThat(recorded.headers["Accept"]).isEqualTo("text/plain")
    assertThat(recorded.headers["Accept-Encoding"]).isEqualTo("gzip, x-gzip, deflate")
    assertThat(recorded.headers["User-Agent"]!!).startsWith("Apache-HttpClient/")
  }

        source.skip(length.toLong())
        return
      }
      dataStream.receiveData(source, length)
      if (inFinished) {
        dataStream.receiveHeaders(Headers.EMPTY, true)
      }
    }

    override fun headers(
      inFinished: Boolean,
      streamId: Int,
      associatedStreamId: Int,
      headerBlock: List<Header>,
    ) {
      if (pushedStream(streamId)) {

# `Response` class

You can declare a parameter in a *path operation function* or dependency to be of type `Response` and then you can set data for the response like headers or cookies.

You can also use it directly to create an instance of it and return it from your *path operations*.

You can import it directly from `fastapi`:

```python
from fastapi import Response
```