│   ├── main.py
│   └── test_main.py
```

Let's say that now the file `main.py` with your **FastAPI** app has some other **path operations**.

It has a `GET` operation that could return an error.

It has a `POST` operation that could return several errors.

Both *path operations* require an `X-Token` header.

//// tab | Python 3.10+

```Python
{!> ../../docs_src/app_testing/app_b_an_py310/main.py!}
```

func (j JSON) Value() (driver.Value, error) {
	if len(j) == 0 {
		return nil, nil
	}
	return json.RawMessage(j).MarshalJSON()
}

type ExampleStruct struct {
	Name string
	Val  string
}

func (s ExampleStruct) Value() (driver.Value, error) {
	return json.Marshal(s)
}

func format(v []byte, escaper string) string {
	return escaper + strings.ReplaceAll(string(v), escaper, escaper+escaper) + escaper
}

   * The caller is responsible for <a
   * href="https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#multipart-form-data">replacing
   * any unpaired carriage return or line feed characters with a CR+LF pair</a> on any non-file
   * inputs before escaping them with this escaper.
   *
   * <p>When escaping a String, the following rules apply:
   *
   * <ul>

}

func (r *testOneByteReadEOF) Read(p []byte) (n int, err error) {
	if r.eof {
		return 0, io.EOF
	}
	n = copy(p, r.data)
	r.eof = true
	return n, io.EOF
}

// Return pointer to testOneByteReadNoEOF{}
func newTestReaderNoEOF(data []byte) io.Reader {
	return &testOneByteReadNoEOF{false, data}
}

// testOneByteReadNoEOF - implements io.Reader which returns 1 byte and nil error, but
// returns io.EOF on the next Read().

    final Queue<Runnable> tasks = new ArrayDeque<>();

    @Override
    public void execute(Runnable command) {
      tasks.add(command);
    }

    boolean hasNext() {
      return !tasks.isEmpty();
    }

    void runNext() {
      assertTrue("expected at least one task to run", hasNext());
      tasks.remove().run();
    }

    void runAll() {
      while (hasNext()) {

  }

  absl::optional<std::vector<int64_t>> make_shape(
      std::vector<int64_t>&& dims) const {
    return absl::make_optional(dims);
  }

  absl::optional<std::vector<int64_t>> unknown_shape() const {
    return absl::nullopt;
  }

  static constexpr int64_t kUnknownDim =
      shape_inference::InferenceContext::kUnknownDim;
  TF_Status* status_;

          public @Nullable Void call() throws Exception {
            // adds two nanoseconds to the ticker
            ticker.advance(1L);
            Thread.sleep(10);
            ticker.advance(1L);
            return null;
          }
        });

    assertEquals(numberOfThreads * 2, ticker.read());
  }

  @GwtIncompatible // concurrency

  public void testConcurrentAutoIncrementStep() throws Exception {

  @CanIgnoreReturnValue
  public RelationshipTester<T> addRelatedGroup(Iterable<? extends T> group) {
    groups.add(ImmutableList.copyOf(group));
    return this;
  }

  public void test() {
    for (int groupNumber = 0; groupNumber < groups.size(); groupNumber++) {
      ImmutableList<T> group = groups.get(groupNumber);

	var err error
	for i := range diskPaths {
		disks[i], diskPaths[i], err = newXLStorageTestSetup(tb)
		if err != nil {
			return nil, err
		}
		err = disks[i].MakeVol(tb.Context(), "testbucket")
		if err != nil {
			return nil, err
		}
	}
	return &erasureTestSetup{dataBlocks, parityBlocks, blockSize, diskPaths, disks}, nil

    val out = Buffer()
    Hpack.Writer(out = out).writeHeaders(sentHeaders)
    return out
  }

  private fun sendHeaderFrames(
    outFinished: Boolean,
    headers: List<Header>,
  ): Buffer {
    val out = Buffer()
    Http2Writer(out, true).headers(outFinished, expectedStreamId, headers)
    return out
  }

  private fun sendPushPromiseFrames(
    streamId: Int,