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

        @Test
        @DisplayName("Should not modify destination buffer")
        void testWriteBytesWireFormatDoesNotModifyBuffer() {
            // Given
            byte[] dst = new byte[100];
            Arrays.fill(dst, (byte) 0xFF);
            byte[] originalDst = dst.clone();

            // When
            response.writeBytesWireFormat(dst, 0);

            // Then
            assertArrayEquals(originalDst, dst);

 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *

The contents that you return from your *path operation function* will be put inside of that `Response`.

/// note

If you use a response class with no media type, FastAPI will expect your response to have no content, so it will not document the response format in its generated OpenAPI docs.

///

## JSON Responses { #json-responses }

* Those schemas will be part of the generated OpenAPI schema, and used by the automatic documentation <abbr title="User Interfaces">UIs</abbr>.

## Automatic docs { #automatic-docs }

The JSON Schemas of your models will be part of your OpenAPI generated schema, and will be shown in the interactive API docs:

<img src="/img/tutorial/body/image01.png">

///

**FastAPI** will do the automatic conversion from the request, so that the parameter `item` receives its specific content and the same for `user`.

It will perform the validation of the compound data, and will document it like that for the OpenAPI schema and automatic docs.

## Singular values in body { #singular-values-in-body }

type xlMetaV2 struct {
	versions []xlMetaV2ShallowVersion

	// data will contain raw data if any.
	// data will be one or more versions indexed by versionID.
	// To remove all data set to nil.
	data xlMetaInlineData

	// metadata version.
	metaV uint8
}

// LoadOrConvert will load the metadata in the buffer.
// If this is a legacy format, it will automatically be converted to XLV2.

 *
 * <ul>
 *   <li>Each {@code Closeable} resource that is successfully registered will be closed later.
 *   <li>If a {@code Throwable} is thrown in the try block, no exceptions that occur when attempting
 *       to close resources will be thrown from the finally block. The throwable from the try block
 *       will be thrown.
 *   <li>If no exceptions or errors were thrown in the try block, the <i>first</i> exception thrown

<img src="/img/tutorial/separate-openapi-schemas/image02.png">
</div>

This means that it will **always have a value**, it's just that sometimes the value could be `None` (or `null` in JSON).

That means that, clients using your API don't have to check if the value exists or not, they can **assume the field will always be there**, but just that in some cases it will have the default value of `None`.