return bytesReceived.get();
    }

    /**
     * Get number of requests sent
     *
     * @return requests sent
     */
    public long getRequestsSent() {
        return requestsSent.get();
    }

    /**
     * Get number of requests received
     *
     * @return requests received
     */
    public long getRequestsReceived() {
        return requestsReceived.get();

    )

    val call1 = client.newCall(Request(server.url("/")))
    call1.execute().use { response ->
      val source = response.body.source()
      assertThat(response.header("h1")).isEqualTo("v1")
      assertThat(source.readUtf8()).isEqualTo("Hello")
      assertThat(response.trailers()).isEqualTo(headersOf("t1", "v2"))
    }

    val call2 = client.newCall(Request(server.url("/")))
    call2.execute().use { response ->

        DeployRequest request = new DeployRequest();

        request.setTrace(RequestTrace.newChild(null, legacySupport.getSession().getCurrentProject()));

        org.eclipse.aether.artifact.Artifact mainArtifact = RepositoryUtils.toArtifact(artifact);
        mainArtifact = mainArtifact.setFile(source);
        request.addArtifact(mainArtifact);

import jakarta.servlet.ServletContext;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServletRequest;

/**
 * The handler of multipart request (fileupload request). <br>
 * This instance is created per one multipart request.
 * @author modified by jflute (originated in Seasar)
 */
public class FessMultipartRequestHandler implements MultipartRequestHandler {

/// tip

The actual callback is just an HTTP request.

When implementing the callback yourself, you could use something like <a href="https://www.python-httpx.org" class="external-link" target="_blank">HTTPX</a> or <a href="https://requests.readthedocs.io/" class="external-link" target="_blank">Requests</a>.

///

## Write the callback documentation code { #write-the-callback-documentation-code }

When deploying applications you will probably want to have some **replication of processes** to take advantage of **multiple cores** and to be able to handle more requests.

As you saw in the previous chapter about [Deployment Concepts](concepts.md){.internal-link target=_blank}, there are multiple strategies you can use.

/// tip | Dica

O callback real é apenas um request HTTP.

Ao implementar o callback por conta própria, você pode usar algo como <a href="https://www.python-httpx.org" class="external-link" target="_blank">HTTPX</a> ou <a href="https://requests.readthedocs.io/" class="external-link" target="_blank">Requests</a>.

///

	}

	var (
		defaultSha256Cksum string
		v                  []string
		ok                 bool
	)

	// For a presigned request we look at the query param for sha256.
	if isRequestPresignedSignatureV4(r) {
		// X-Amz-Content-Sha256, if not set in presigned requests, checksum
		// will default to 'UNSIGNED-PAYLOAD'.
		defaultSha256Cksum = unsignedPayload
		v, ok = r.Form[xhttp.AmzContentSha256]
		if !ok {

            throws VersionResolutionException {
        RequestTrace trace = RequestTrace.newChild(request.getTrace(), request);

        Artifact artifact = request.getArtifact();

        String version = artifact.getVersion();

        VersionResult result = new VersionResult(request);

        Key cacheKey = null;

                        })),
                null);
        InternalSession.associate(session, iSession);

        ArtifactResolutionResult result = repositorySystem.resolve(request);
        resolutionErrorHandler.throwErrors(request, result);
        assertEquals(2, result.getArtifacts().size());

        //
        // System scoped version which should
        //
        d.setScope(Artifact.SCOPE_SYSTEM);