all CRDs to be present. On each upgrade it is recommended to reapply the file, to make sure
you get all CRDs.  CRDs are separated by release and by component type in the CRD directory.

Istio has strong integration with certmanager.  Some operators may want to keep their current certmanager
CRDs in place and not have Istio modify them. In this case, it is necessary to apply CRD files individually.

```bash
kubectl apply -k github.com/istio/installer/base

import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Map;
import java.util.Objects;

import org.apache.maven.model.InputSource;
import org.apache.maven.model.Model;

      (d) If the Work includes a "NOTICE" text file as part of its
          distribution, then any Derivative Works that You distribute must
          include a readable copy of the attribution notices contained
          within such NOTICE file, excluding those notices that do not
          pertain to any part of the Derivative Works, in at least one
          of the following places: within a NOTICE text file distributed

      (d) If the Work includes a "NOTICE" text file as part of its
          distribution, then any Derivative Works that You distribute must
          include a readable copy of the attribution notices contained
          within such NOTICE file, excluding those notices that do not
          pertain to any part of the Derivative Works, in at least one
          of the following places: within a NOTICE text file distributed

      (d) If the Work includes a "NOTICE" text file as part of its
          distribution, then any Derivative Works that You distribute must
          include a readable copy of the attribution notices contained
          within such NOTICE file, excluding those notices that do not
          pertain to any part of the Derivative Works, in at least one
          of the following places: within a NOTICE text file distributed

      (d) If the Work includes a "NOTICE" text file as part of its
          distribution, then any Derivative Works that You distribute must
          include a readable copy of the attribution notices contained
          within such NOTICE file, excluding those notices that do not
          pertain to any part of the Derivative Works, in at least one
          of the following places: within a NOTICE text file distributed

    /**
     * A directory to store downloaded files.
     */
    protected File baseDir;

    protected File createFile(final String path) {
        final String[] paths = path.split("/");
        File targetFile = baseDir;
        for (int i = 0; i < paths.length - 1; i++) {
            File file = new File(targetFile, paths[i]);
            if (file.exists()) {
                if (!file.isDirectory()) {

                        updateCheckManager.touch(metadata, repository, file);
                    }
                }

                // TODO should this be inside the above check?
                // touch file so that this is not checked again until interval has passed
                if (file.exists()) {
                    file.setLastModified(System.currentTimeMillis());
                }
            }

    private static final String NAME_PREFIX = "backupTest_";
    private static final String API_PATH = "/api/admin/backup";
    private static final String LIST_ENDPOINT_SUFFIX = "files";
    private static final String ITEM_ENDPOINT_SUFFIX = "file";

    private static final String KEY_PROPERTY = "";

    @Override
    protected String getNamePrefix() {
        return NAME_PREFIX;
    }

    @Override

 *
 * All event methods must execute fast, without external locking, cannot throw exceptions,
 * attempt to mutate the event parameters, or be reentrant back into the client.
 * Any IO - writing to files or network should be done asynchronously.
 */
@ExperimentalOkHttpApi
abstract class ConnectionListener {
  /**
   * Invoked as soon as a call causes a connection to be started.
   */
  open fun connectStart(