**Note**: You can mix `def` and `async def` in your *path operation functions* as much as you need and define each one using the best option for you. FastAPI will do the right thing with them.

Anyway, in any of the cases above, FastAPI will still work asynchronously and be extremely fast.

But by following the steps above, it will be able to do some performance optimizations.

## Technical Details { #technical-details }

        @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);

    void testInitDefaultsWithPresetMachineId() throws Exception {
        BaseConfiguration testConfig = new BaseConfiguration(false);
        byte[] customMachineId = new byte[32];
        Arrays.fill(customMachineId, (byte) 0xFF);

        // Use reflection to set private field
        java.lang.reflect.Field machineIdField = BaseConfiguration.class.getDeclaredField("machineId");
        machineIdField.setAccessible(true);

            // Write valid response data
            SMBUtil.writeInt4(15, buffer, 0);
            SMBUtil.writeInt4(16384, buffer, 4);
            SMBUtil.writeInt4(245760, buffer, 8);
            // Fill rest with random data
            for (int i = 12; i < buffer.length; i++) {
                buffer[i] = (byte) (i % 256);
            }

            int bytesDecoded = response.decode(buffer, 0, buffer.length);

 * 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.
 *

        },
        "italian_elision": {
          "type":         "elision",
          "articles": [
                "c", "l", "all", "dall", "dell",
                "nell", "sull", "coll", "pell",
                "gl", "agl", "dagl", "degl", "negl",
                "sugl", "un", "m", "t", "s", "v", "d"
          ]
        },
        "italian_stop": {
          "type":       "stop",

							<em class="fa fa-search">
						</button>
					</div>
				</div>
			</form>
		</c:if>
		<nav class="mt-2">

		<ul class="nav nav-pills nav-sidebar flex-column" data-widget="treeview" role="menu">
			<li class="nav-header"><la:message key="labels.sidebar.menu" /></li>
			<c:if test="${fe:permission('admin-dashboard-view')}">
				<li class="nav-item">

                size = sfd.getInitialSize();
                resumeKey = rkresp.getResumeKey();

                // start with some reasonably safe defaults, the server will till us if it does not like it
                // can we resume this if we loose the file descriptor?

                int maxChunks = 256;
                int maxChunkSize = 1024 * 1024;

    void testWithLargeBuffers() {
        // Test with large byte arrays
        byte[] largeRequestBuffer = new byte[1024];
        byte[] largeResponseBuffer = new byte[2048];

        // Fill with some test data
        for (int i = 0; i < largeRequestBuffer.length; i++) {
            largeRequestBuffer[i] = (byte) (i % 256);
        }
        for (int i = 0; i < largeResponseBuffer.length; i++) {

///

**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 }