fi := metadata[index]
			// Assign index when index is initialized
			if fi.Erasure.Index == 0 {
				fi.Erasure.Index = index + 1
			}

			if !fi.IsValid() {
				return errFileCorrupt
			}
			resp, err := disks[index].RenameData(ctx, srcBucket, srcEntry, fi, dstBucket, dstEntry, RenameOptions{})
			if err != nil {
				return err
			}
			diskVersions[index] = resp.Sign

                break;
            }
        }

        this.canon = new String(out, 0, prefixLen);
        if (prefixLen > 1) {
            prefixLen--;
            final int firstSep = this.canon.indexOf('/', 1);
            if (firstSep < 0) {
                this.share = this.canon.substring(1);
                this.unc = "\\";
            } else if (firstSep == prefixLen) {

Let's take this application as example:

{* ../../docs_src/query_params_str_validations/tutorial001_py310.py hl[7] *}

The query parameter `q` is of type `str | None`, that means that it's of type `str` but could also be `None`, and indeed, the default value is `None`, so FastAPI will know it's not required.

/// note

FastAPI will know that the value of `q` is not required because of the default value `= None`.

            return StringUtil.EMPTY; // empty
        }

        if (url.startsWith("file:////")) {
            final String value = decodeUrlAsName(url.substring(9), true);
            final int pos = value.indexOf('/');
            if (pos > 0) {
                return value.substring(0, pos);
            }
            if (pos == -1) {
                return value;
            }
            return "localhost";

HSPLkotlin/text/StringsKt__StringsKt;->getLastIndex(Ljava/lang/CharSequence;)I
HSPLkotlin/text/StringsKt__StringsKt;->indexOf$default(Ljava/lang/CharSequence;CIZI)I
HSPLkotlin/text/StringsKt__StringsKt;->indexOf$default(Ljava/lang/CharSequence;Ljava/lang/String;IZI)I
HSPLkotlin/text/StringsKt__StringsKt;->indexOf(Ljava/lang/CharSequence;Ljava/lang/String;IZ)I

astDay:"[wa\u2019Hu\u2019] LT",lastWeek:"LLL",sameElse:"L"},relativeTime:{future:function(e){var a=e;return a=-1!==e.indexOf("jaj")?a.slice(0,-3)+"leS":-1!==e.indexOf("jar")?a.slice(0,-3)+"waQ":-1!==e.indexOf("DIS")?a.slice(0,-3)+"nem":a+" pIq"},past:function(e){var a=e;return a=-1!==e.indexOf("jaj")?a.slice(0,-3)+"Hu\u2019":-1!==e.indexOf("jar")?a.slice(0,-3)+"wen":-1!==e.indexOf("DIS")?a.slice(0,-3)+"ben":a+" ret"},s:"puS lup",ss:Wr,m:"wa\u2019 tup",mm:Wr,h:"wa\u2019 rep",hh:Wr,d:"wa\u2019 jaj",dd:Wr,M:"wa\u2019...

  public final <K> ImmutableListMultimap<K, @NonNull E> index(Function<? super E, K> keyFunction) {
    return Multimaps.index((Iterable<@NonNull E>) getDelegate(), keyFunction);
  }

  /**
   * Returns a map with the contents of this {@code FluentIterable} as its {@code values}, indexed
   * by keys derived from those values. In other words, each input value produces an entry in the

  public final <K> ImmutableListMultimap<K, @NonNull E> index(Function<? super E, K> keyFunction) {
    return Multimaps.index((Iterable<@NonNull E>) getDelegate(), keyFunction);
  }

  /**
   * Returns a map with the contents of this {@code FluentIterable} as its {@code values}, indexed
   * by keys derived from those values. In other words, each input value produces an entry in the

     * @return The file type helper.
     */
    public static FileTypeHelper getFileTypeHelper() {
        return getComponent(FILE_TYPE_HELPER);
    }

    /**
     * Gets the index updater component.
     * @return The index updater.
     */
    public static IndexUpdater getIndexUpdater() {
        return getComponent(INDEX_UPDATER);
    }

    /**
     * Gets the key match helper component.

![Swagger-Oberfläche](https://fastapi.tiangolo.com/img/index/index-01-swagger-ui-simple.png)

## Alternative API-Dokumentation