NtlmChallenge nc = new NtlmChallenge(challenge, dc);
            String result = nc.toString();

            // The format is: NtlmChallenge[challenge=0x<hex>,dc=<dc_string>]
            assertTrue(result.startsWith("NtlmChallenge[challenge=0x"));
            assertTrue(result.endsWith(",dc=SERVER123]"));

            // Hexdump.toHexString with size = length * 2 produces 8 uppercase hex chars

## Description from docstring { #description-from-docstring }

As descriptions tend to be long and cover multiple lines, you can declare the *path operation* description in the function <abbr title="a multi-line string as the first expression inside a function (not assigned to any variable) used for documentation">docstring</abbr> and **FastAPI** will read it from there.

        final String docString = getXmlString(document);
        final String pnString = getXmlString(pruneNode);
        assertTrue(docString.contains("<SCRIPT>"));
        assertTrue(docString.contains("foo"));
        assertTrue(docString.contains("<NOSCRIPT>"));
        assertTrue(docString.contains("bar"));
        assertTrue(pnString.contains("<SCRIPT>"));

{* ../../docs_src/path_operation_advanced_configuration/tutorial003.py hl[6] *}

## Advanced description from docstring { #advanced-description-from-docstring }

You can limit the lines used from the docstring of a *path operation function* for OpenAPI.

Adding an `\f` (an escaped "form feed" character) causes **FastAPI** to truncate the output used for OpenAPI at this point.

> port         (port)               MySQL server port (used only if `dsn_string` is empty)
> username     (string)             database username (used only if `dsn_string` is empty)
> password     (string)             database password (used only if `dsn_string` is empty)
> database     (string)             database name (used only if `dsn_string` is empty)
> ```
>

  }

  public static void assertEqualIgnoringOrder(Iterable<?> expected, Iterable<?> actual) {
    List<?> exp = copyToList(expected);
    List<?> act = copyToList(actual);
    String actString = act.toString();

    // Of course we could take pains to give the complete description of the
    // problem on any failure.

    // Yeah it's n^2.
    for (Object object : exp) {

  }

  private static final Comparator<Object> TO_STRING =
      new Comparator<Object>() {
        @Override
        public int compare(Object o1, Object o2) {
          return o1.toString().compareTo(o2.toString());
        }
      };

  public void testSupertypeComparator() {
    SortedSet<Integer> set =
        new ImmutableSortedSet.Builder<Integer>(TO_STRING).add(3, 12, 101, 44).build();

| iss        | _string_       | The issuer of the JWT. The '> Identity Provider Entity Id ' value of the OAuth2/OpenID Connect Inbound Authentication configuration of the Resident Identity Provider is returned here. |
| aud        | _string array_ | The token audience list. The client identifier of the OAuth clients that the JWT is intended for, is sent herewith.                                                                     |

It is a plug-in for many frameworks (and there's a plug-in for Starlette too).

The way it works is that you write the definition of the schema using YAML format inside the docstring of each function handling a route.

And it generates OpenAPI schemas.

That's how it works in Flask, Starlette, Responder, etc.

* Add support for truncating docstrings from *path operation functions*.
    * New docs at [Advanced description from docstring](https://fastapi.tiangolo.com/advanced/path-operation-advanced-configuration/#advanced-description-from-docstring).
    * PR [#556](https://github.com/tiangolo/fastapi/pull/556) by [@svalouch](https://github.com/svalouch).