There are several custom response classes you can use to create an instance and return them directly from your *path operations*.

Read more about it in the [FastAPI docs for Custom Response - HTML, Stream, File, others](https://fastapi.tiangolo.com/advanced/custom-response/).

You can import them directly from `fastapi.responses`:

```python
from fastapi.responses import (
    FileResponse,
    HTMLResponse,

        stats.put("fs", getFsObj());
        return asJson(new ApiStatsResponse().stats(stats).status(ApiResult.Status.OK).result());
    }

    private FsObj[] getFsObj() {
        return Arrays.stream(File.listRoots()).map(f -> {
            final FsObj fsObj = new FsObj();
            fsObj.path = f.getAbsolutePath();
            fsObj.free = f.getFreeSpace();
            fsObj.total = f.getTotalSpace();

 */
package org.codelibs.fess.app.web.api.admin.reqheader;

import static org.codelibs.fess.app.web.admin.reqheader.AdminReqheaderAction.getRequestHeader;

import java.util.List;
import java.util.stream.Collectors;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.codelibs.fess.app.pager.ReqHeaderPager;
import org.codelibs.fess.app.service.RequestHeaderService;

 */
package org.codelibs.fess.app.web.api.admin.webauth;

import static org.codelibs.fess.app.web.admin.webauth.AdminWebauthAction.getWebAuthentication;

import java.util.List;
import java.util.stream.Collectors;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.codelibs.fess.app.pager.WebAuthPager;
import org.codelibs.fess.app.service.WebAuthenticationService;

  private void writeObject(ObjectOutputStream stream) throws IOException {
    stream.defaultWriteObject();
    stream.writeObject(elementSet().comparator());
    Serialization.writeMultiset(this, stream);
  }

  @J2ktIncompatible
  @GwtIncompatible // java.io.ObjectInputStream
  private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
    stream.defaultReadObject();

  }

  @Override
  public boolean wasStreamClosed() {
    return byteSink.wasStreamClosed();
  }

  @Override
  public Writer openStream() throws IOException {
    // using TestByteSink's output stream to get option behavior, so flush to it on every write
    return new FilterWriter(new OutputStreamWriter(byteSink.openStream(), UTF_8)) {
      @Override
      public void write(int c) throws IOException {
        super.write(c);

	args.QuoteEscapeCharacter = defaultQuoteEscapeCharacter
	args.CommentCharacter = defaultCommentCharacter
	args.AllowQuotedRecordDelimiter = false

	for {
		// Read tokens from the XML document in a stream.
		t, err := d.Token()
		if err != nil {
			if err == io.EOF {
				break
			}
			return err
		}

		if se, ok := t.(xml.StartElement); ok {
			tagName := se.Name.Local
			switch tagName {

        saveLayout(writer, typed);
    }

    /**
     * Store a properties into a output stream, preserving comments, special character, etc.
     * This method is mainly to be compatible with the java.util.Properties class.
     *
     * @param os an output stream.
     * @param comment this parameter is ignored as this Properties
     * @throws IOException If storing fails
     */

  }

  /**
   * Consume the next header in the stream and return it. If there is no header to read because we
   * have reached a limit, this returns [END_OF_DATA].
   */
  internal fun readHeader(): DerHeader {
    require(peekedHeader == null)

    // We've hit a local limit.
    if (byteCount == limit) return END_OF_DATA

    // We've exhausted the source stream.

  private void writeObject(ObjectOutputStream stream) throws IOException {
    stream.defaultWriteObject();
    stream.writeObject(elementSet().comparator());
    Serialization.writeMultiset(this, stream);
  }

  @J2ktIncompatible
  @GwtIncompatible // java.io.ObjectInputStream
  private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
    stream.defaultReadObject();