If an incoming request does not validate correctly then a `400` response will be sent.

## `GZipMiddleware` { #gzipmiddleware }

Handles GZip responses for any request that includes `"gzip"` in the `Accept-Encoding` header.

The middleware will handle both standard and streaming responses.

{* ../../docs_src/advanced_middleware/tutorial003_py39.py hl[2,6] *}

The following arguments are supported:

import org.apache.maven.model.DependencyManagement;
import org.apache.maven.model.Model;
import org.apache.maven.model.building.ModelBuildingRequest;
import org.apache.maven.model.building.ModelProblemCollector;

/**
 * Handles the import of dependency management from other models into the target model.
 *
 * @deprecated use {@code org.apache.maven.api.services.ModelBuilder} instead
 */
@Deprecated(since = "4.0.0")

import org.apache.maven.model.Model;
import org.apache.maven.model.building.ModelBuildingRequest;
import org.apache.maven.model.building.ModelProblemCollector;
import org.apache.maven.model.merge.MavenModelMerger;

/**
 * Handles injection of dependency management into the model.
 *
 * @deprecated use {@code org.apache.maven.api.services.ModelBuilder} instead
 */
@SuppressWarnings({"checkstyle:methodname"})
@Named
@Singleton

    }
  }

  override fun getSelectedProtocol(sslSocket: SSLSocket): String? =
    if (sslSocket is org.openjsse.javax.net.ssl.SSLSocket) {
      when (val protocol = sslSocket.applicationProtocol) {
        // Handles both un-configured and none selected.
        null, "" -> null
        else -> protocol
      }
    } else {
      super.getSelectedProtocol(sslSocket)
    }

  companion object {

import java.util.Objects;

import org.apache.maven.api.toolchain.InputSource;
import org.apache.maven.toolchain.model.PersistedToolchains;
import org.apache.maven.toolchain.v4.MavenToolchainsStaxReader;

/**
 * Handles deserialization of toolchains from the default textual format.
 *
 * @since 3.3.0
 * @deprecated since 4.0.0, use {@link MavenToolchainsStaxReader} instead
 */
@Named
@Singleton
@Deprecated(since = "4.0.0")

import org.codehaus.plexus.util.ReaderFactory;
import org.codehaus.plexus.util.xml.XmlStreamReader;
import org.codehaus.plexus.util.xml.pull.XmlPullParserException;

/**
 * Handles deserialization of a model from some kind of textual format like XML.
 *
 * @deprecated use {@link org.apache.maven.model.v4.MavenStaxReader} instead
 */
@Named
@Singleton
@Deprecated(since = "4.0.0")

import org.apache.maven.model.building.ModelBuildingRequest;
import org.apache.maven.model.building.ModelProblemCollector;
import org.apache.maven.model.merge.MavenModelMerger;

/**
 * Handles injection of plugin management into the model.
 *
 * @deprecated use {@code org.apache.maven.api.services.ModelBuilder} instead
 */
@SuppressWarnings({"checkstyle:methodname"})
@Named
@Singleton

import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.io.Writer;
import java.util.Map;

import org.apache.maven.settings.Settings;

/**
 * Handles serialization of settings into some kind of textual format like XML.
 *
 * @deprecated since 4.0.0, use {@link org.apache.maven.api.services.xml.SettingsXmlFactory} instead
 */
@Deprecated(since = "4.0.0")

    }
  }

  override fun getSelectedProtocol(sslSocket: SSLSocket): String? =
    if (sslSocket is BCSSLSocket) {
      when (val protocol = (sslSocket as BCSSLSocket).applicationProtocol) {
        // Handles both un-configured and none selected.
        null, "" -> null
        else -> protocol
      }
    } else {
      super.getSelectedProtocol(sslSocket)
    }

  companion object {

import java.nio.file.Files;
import java.util.Map;
import java.util.Objects;

import org.apache.maven.artifact.repository.metadata.Metadata;
import org.apache.maven.metadata.v4.MetadataStaxReader;

/**
 * Handles deserialization of metadata from some kind of textual format like XML.
 *
 */
@Named
@Singleton
public class DefaultMetadataReader implements MetadataReader {

    @Override