# - navigation.instant.preview
  - navigation.instant.progress
  - navigation.path
  - navigation.tabs
  - navigation.tabs.sticky
  - navigation.top
  - navigation.tracking
  - search.highlight
  - search.share
  - search.suggest
  - toc.follow

  icon:
    repo: fontawesome/brands/github-alt
  logo: img/icon-white.svg
  favicon: img/favicon.png
  language: en
repo_name: fastapi/fastapi

```Python hl_lines="14-17" title="app/main.py"
{!../../docs_src/bigger_applications/app/main.py!}
```

That way, the original `APIRouter` will stay unmodified, so we can still share that same `app/internal/admin.py` file with other projects in the organization.

The result is that in our app, each of the *path operations* from the `admin` module will have:

* The prefix `/admin`.
* The tag `admin`.

   *         .collect(
   *             flatteningToImmutableSetMultimap(
   *                  str -> str.charAt(0),
   *                  str -> str.substring(1).chars().mapToObj(c -> (char) c));
   *
   * // is equivalent to
   *
   * static final ImmutableSetMultimap<Character, Character> FIRST_LETTER_MULTIMAP =
   *     ImmutableSetMultimap.<Character, Character>builder()

                .map(HttpServletRequest::getCharacterEncoding).orElse(Constants.UTF_8);
        final StringBuilder buf = new StringBuilder(url.length() + 100);
        for (final char c : url.toCharArray()) {
            if (CharUtil.isUrlChar(c)) {
                buf.append(c);
            } else {
                try {
                    buf.append(URLEncoder.encode(String.valueOf(c), enc));

   * @param off the offset into the buffer
   * @param len the number of characters to process
   * @throws IOException if an I/O error occurs
   * @see #finish
   */
  protected void add(char[] cbuf, int off, int len) throws IOException {
    int pos = off;
    if (sawReturn && len > 0) {
      // Last call to add ended with a CR; we can handle the line now.
      if (finishLine(cbuf[pos] == '\n')) {
        pos++;

   * @param off the offset into the buffer
   * @param len the number of characters to process
   * @throws IOException if an I/O error occurs
   * @see #finish
   */
  protected void add(char[] cbuf, int off, int len) throws IOException {
    int pos = off;
    if (sawReturn && len > 0) {
      // Last call to add ended with a CR; we can handle the line now.
      if (finishLine(cbuf[pos] == '\n')) {
        pos++;

    try {
      return new File(url.toURI()); // Accepts escaped characters like %20.
    } catch (URISyntaxException e) { // URL.toURI() doesn't escape chars.
      return new File(url.getPath()); // Accepts non-escaped chars like space.
    }
  }

 the version number 2.1.)

                            Preamble

  The licenses for most software are designed to take away your
freedom to share and change it.  By contrast, the GNU General Public
Licenses are intended to guarantee your freedom to share and change
free software--to make sure the software is free for all its users.

  This license, the Lesser General Public License, applies to some

  @Override
  public boolean containsAll(Collection<?> targets) {
    // TODO(jlevy): For optimal performance, use a binary search when
    // targets.size() < size() / log(size())
    // TODO(kevinb): see if we can share code with OrderedIterator after it
    // graduates from labs.
    if (targets instanceof Multiset) {
      targets = ((Multiset<?>) targets).elementSet();
    }

    checkOpen();
    requireNonNull(seq); // safe because of checkOpen
    return hasRemaining() ? seq.charAt(pos++) : -1;
  }

  @Override
  public synchronized int read(char[] cbuf, int off, int len) throws IOException {
    checkPositionIndexes(off, off + len, cbuf.length);
    checkOpen();
    requireNonNull(seq); // safe because of checkOpen
    if (!hasRemaining()) {
      return -1;