Nevertheless, we can declare the expected schema for the request body.

### Custom OpenAPI content type { #custom-openapi-content-type }

        // Protocol ID
        System.arraycopy(new byte[] { (byte) 0xFE, 'S', 'M', 'B' }, 0, buffer, bufferIndex, 4);
        // Header length
        SMBUtil.writeInt2(64, buffer, bufferIndex + 4);
        // Credit charge
        SMBUtil.writeInt2(1, buffer, bufferIndex + 6);
        // Status
        SMBUtil.writeInt4(0, buffer, bufferIndex + 8);
        // Command - SMB2_SET_INFO (0x0011)

#### Define a *path operation decorator* { #define-a-path-operation-decorator }

{* ../../docs_src/first_steps/tutorial001.py hl[6] *}

The `@app.get("/")` tells **FastAPI** that the function right below is in charge of handling requests that go to:

* the path `/`
* using a <abbr title="an HTTP GET method"><code>get</code> operation</abbr>

/// info | `@decorator` Info

When you do this, the examples will be part of the internal **JSON Schema** for that body data.

Nevertheless, at the <abbr title="2023-08-26">time of writing this</abbr>, Swagger UI, the tool in charge of showing the docs UI, doesn't support showing multiple examples for the data in **JSON Schema**. But read below for a workaround.

### OpenAPI-specific `examples` { #openapi-specific-examples }

///

## Override the default exception handlers { #override-the-default-exception-handlers }

**FastAPI** has some default exception handlers.

These handlers are in charge of returning the default JSON responses when you `raise` an `HTTPException` and when the request has invalid data.

You can override these exception handlers with your own.

        assertNotNull(responseWithNull);
    }

    @Test
    @DisplayName("Should handle large data offset value")
    void testReadBytesWireFormatLargeDataOffset() throws Exception {
        // Given
        byte[] buffer = new byte[512];
        int bodyStart = 0;
        int dataLength = 10;
        // Use a large but safe offset value that fits in signed byte range (120)
        int dataOffsetValue = 120;

     *
     * @param credit
     *            the credit to set
     */
    public final void setCredit(final int credit) {
        this.credit = credit;
    }

    /**
     * Gets the credit charge for this message.
     *
     * @return the creditCharge
     */
    public final int getCreditCharge() {
        return this.creditCharge;
    }

    @Override
    public void retainPayload() {

            assertEquals(0, testMessage.getCredit());
            testMessage.setCredit(100);
            assertEquals(100, testMessage.getCredit());
        }

        @Test
        @DisplayName("Should get credit charge")
        void testCreditChargeProperty() {
            assertEquals(0, testMessage.getCreditCharge());
        }

        @Test
        @DisplayName("Should get and set read size")

## Where are Packages Installed { #where-are-packages-installed }

When you install Python, it creates some directories with some files in your computer.

Some of these directories are the ones in charge of having all the packages you install.

When you run:

<div class="termy">

```console
// Don't run this now, it's just an example 🤓
$ pip install "fastapi[standard]"
---> 100%
```

When the **container** is started and running (started from a **container image**) it could create or change files, environment variables, etc. Those changes will exist only in that container, but would not persist in the underlying container image (would not be saved to disk).