* limits, this call may be executed well before processing the request is able to begin.
   *
   * This will be invoked only once for a single [Call]. Retries of different routes or redirects
   * will be handled within the boundaries of a single [callStart] and [callEnd]/[callFailed] pair.
   */
  open fun callStart(call: Call) {
  }

  /**
   * Invoked prior to a proxy selection.
   *

### Using MinIO Console

- Open MinIO URL on the browser, lets say <http://localhost:9000/>
- Click on `Login with SSO`
- User will be redirected to the Keycloak user login page, upon successful login the user will be redirected to MinIO page and logged in automatically,
  the user should see now the buckets and objects they have access to.

## Explore Further

    when certificates matched but the DNS addresses did not. This would only occur when following a
    redirect from one hostname to another, and where both hosts had common certificates.

 *  Fix: Don't fail on a redirect when a client has configured a 'trust everything' trust manager.
    Typically this would cause certain redirects to fail in debug and development configurations.


## Version 4.4.0

_2020-02-17_

   * * It may be the request generated in response to an HTTP redirect or authentication
   *   challenge. In this case the request URL may be different than the initial request URL.
   *
   * Use the `request` of the [networkResponse] field to get the wire-level request that was
   * transmitted. In the case of follow-ups and redirects, also look at the `request` of the

 * currently carrying zero streams is an idle stream. We keep it alive because reusing an existing
 * connection is typically faster than establishing a new one.
 *
 * When a single logical call requires multiple streams due to redirects or authorization
 * challenges, we prefer to use the same physical connection for all streams in the sequence. There
 * are potential performance and behavior consequences to this preference. To support this feature,

### Things to consider

MinIO redirects browser access requests to the configured server port (i.e. `127.0.0.1:9000`) to the configured Console port. MinIO uses the hostname or IP address specified in the request when building the redirect URL. The URL and port *must* be accessible by the client for the redirection to work.

    method: String,
  ): Request? {
    // Does the client allow redirects?
    if (!client.followRedirects) return null

    val location = userResponse.header("Location") ?: return null
    // Don't follow redirects to unsupported protocols.
    val url = userResponse.request.url.resolve(location) ?: return null

    // If configured, don't follow redirects between SSL and non-SSL.

    <error-code>400</error-code>
    <location>/WEB-INF/view/error/redirect.jsp?type=badRequest</location>
  </error-page>
  <error-page>
    <error-code>401</error-code>
    <location>/WEB-INF/view/error/redirect.jsp?type=badAuth</location>
  </error-page>
  <error-page>
    <error-code>403</error-code>
    <location>/WEB-INF/view/error/redirect.jsp?type=logOut</location>
  </error-page>
  <error-page>

 *  Fix: Handle response code `308 Permanent Redirect`.
 *  Fix: Don't skip the callback if a call is canceled.
 *  Fix: Permit hostnames with underscores.
 *  Fix: Permit overriding the content-type in `OkApacheClient`.
 *  Fix: Use the socket factory for direct connections.
 *  Fix: Honor `OkUrlFactory` APIs that disable redirects.
 *  Fix: Don't crash on concurrent modification of `SPDY` SPDY settings.

            return redirect(ErrorAction.class);
        }
        final String url = DocumentUtil.getValue(doc, fessConfig.getIndexFieldUrl(), String.class);
        if (url == null) {
            saveError(messages -> messages.addErrorsDocumentNotFound(GLOBAL, form.docId));
            return redirect(ErrorAction.class);
        }

        if (fessConfig.isSearchLog()) {