The response object will also have autocompletion:

<img src="/img/tutorial/generate-clients/image05.png">

## FastAPI App with Tags { #fastapi-app-with-tags }

In many cases, your FastAPI app will be bigger, and you will probably use tags to separate different groups of *path operations*.

For example, you could have a section for **items** and another section for **users**, and they could be separated by tags:

     * The error's stacktrace will be output when this error level is enabled.
     *
     * @param content
     * @param error
     */
    void debug(CharSequence content, Throwable error);

    /**
     * Send an exception to the user in the <b>debug</b> error level.<br>
     * The stack trace for this exception will be output when this error level is enabled.
     *
     * @param error

     * mirror, its URL and ID will be updated to match the values from the mirror specification. Repositories without a
     * matching mirror will pass through unchanged. Note: This method must be called before
     * {@link #injectAuthentication(List, List)} or the repositories will end up with the wrong credentials.
     *

{* ../../docs_src/security/tutorial001_an_py39.py hl[12] *}

This dependency will provide a `str` that is assigned to the parameter `token` of the *path operation function*.

**FastAPI** will know that it can use this dependency to define a "security scheme" in the OpenAPI schema (and the automatic API docs).

/// info | Technical Details

   *
   * <p>Exceptions thrown by a listener will be propagated up to the executor. Any exception thrown
   * during {@code Executor.execute} (e.g., a {@code RejectedExecutionException} or an exception
   * thrown by {@linkplain MoreExecutors#directExecutor direct execution}) will be caught and
   * logged.
   *
   * <p>Note: If your listener is lightweight -- and will not cause stack overflow by completing

     * specified by the <code>UniAddress</code> parameter. If the credentials are
     * not accepted, an <code>SmbAuthException</code> will be thrown. If an error
     * occurs an <code>SmbException</code> will be thrown. If the credentials are
     * valid, the method will return without throwing an exception. See the
     * last <a href="../../../faq.html">FAQ</a> question.
     * <p>

/// tip

All this might not seem as useful with these simple examples.

But you will see how useful it is in the chapters about **security**.

And you will also see the amounts of code it will save you.

You can write <a href="https://en.wikipedia.org/wiki/Markdown" class="external-link" target="_blank">Markdown</a> in the docstring, it will be interpreted and displayed correctly (taking into account docstring indentation).

{* ../../docs_src/path_operation_configuration/tutorial004_py310.py hl[17:25] *}

It will be used in the interactive docs:

    void testWriteParametersWireFormatPreservesBuffer() {
        querySecurityDesc = new NtTransQuerySecurityDesc(mockConfig, 0x1234, OWNER_SECURITY_INFORMATION);
        byte[] dst = new byte[20];

        // Fill buffer with test pattern
        for (int i = 0; i < dst.length; i++) {
            dst[i] = (byte) (i & 0xFF);
        }

        int startIndex = 5;

        int[] invalidSizes = { -1, 0, 1, 2, 3, 5, 6, 8, 16, 32, 64, 128, 256, 512, 1024 };

        for (int invalidSize : invalidSizes) {
            byte[] buffer = new byte[256];

            // Handle negative values (will wrap around in writeInt2)
            if (invalidSize >= 0) {
                SMBUtil.writeInt2(invalidSize, buffer, 0);

                // When & Then