assertThrows(IllegalArgumentException.class, () -> Range.atLeast(2).gap(Range.atLeast(1)));

    assertThrows(IllegalArgumentException.class, () -> Range.atMost(1).gap(Range.atMost(2)));

    assertThrows(IllegalArgumentException.class, () -> Range.atMost(2).gap(Range.atMost(1)));
  }

  public void testGap_connectedAdjacentYieldsEmpty() {
    Range<Integer> range = Range.open(3, 4);

    assertThrows(IllegalArgumentException.class, () -> Range.atLeast(2).gap(Range.atLeast(1)));

    assertThrows(IllegalArgumentException.class, () -> Range.atMost(1).gap(Range.atMost(2)));

    assertThrows(IllegalArgumentException.class, () -> Range.atMost(2).gap(Range.atMost(1)));
  }

  public void testGap_connectedAdjacentYieldsEmpty() {
    Range<Integer> range = Range.open(3, 4);

    assertEquals(empty, Maps.subMap(map, Range.atMost(0)));
    assertEquals(ImmutableSortedMap.of(2, 0, 4, 0), Maps.subMap(map, Range.atMost(4)));
    assertEquals(ImmutableSortedMap.of(2, 0, 4, 0, 6, 0), Maps.subMap(map, Range.atMost(7)));
    assertEquals(map, Maps.subMap(map, Range.atMost(20)));
  }

  @GwtIncompatible // NavigableMap
  public void testSubMap_unboundedRange() {

It was deprecated from Starlette, but if you have code that used it, you can easily **migrate** to [starlette-graphene3](https://github.com/ciscorn/starlette-graphene3), that covers the same use case and has an **almost identical interface**.

/// tip

If you need GraphQL, I still would recommend you check out [Strawberry](https://strawberry.rocks/), as it's based on type annotations instead of custom classes and types.

///

* **FastAPI**:
    * The same way that Starlette uses Uvicorn and cannot be faster than it, **FastAPI** uses Starlette, so it cannot be faster than it.
    * FastAPI provides more features on top of Starlette. Features that you almost always need when building APIs, like data validation and serialization. And by using it, you get automatic documentation for free (the automatic documentation doesn't even add overhead to running applications, it is generated on startup).

    * An example is `404`, for a "Not Found" response.
    * For generic errors from the client, you can just use `400`.
* `500 - 599` are for server errors. You almost never use them directly. When something goes wrong at some part in your application code, or server, it will automatically return one of these status codes.

/// tip

A **request** body is data sent by the client to your API. A **response** body is the data your API sends to the client.

Your API almost always has to send a **response** body. But clients don't necessarily need to send **request bodies** all the time, sometimes they only request a path, maybe with some query parameters, but don't send a body.

By the spec, you should return a JSON with an `access_token` and a `token_type`, the same as in this example.

This is something that you have to do yourself in your code, and make sure you use those JSON keys.

It's almost the only thing that you have to remember to do correctly yourself, to be compliant with the specifications.

For the rest, **FastAPI** handles it for you.

///

* `security`: Security Fixes
    * This is for security fixes, like vulnerabilities. It would almost never be used.
* `feature`: Features
    * New features, adding support for things that didn't exist before.
* `bug`: Fixes

        Collections2.orderedPermutations(
                newArrayList(
                    1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21))
            .size());

    // Almost force an overflow in the binomial coefficient calculation
    assertEquals(
        1391975640 /*C(34,14)*/,
        Collections2.orderedPermutations(concat(nCopies(20, 1), nCopies(14, 2))).size());