]
}
```

## Recap { #recap }

Declare headers with `Header`, using the same common pattern as `Query`, `Path` and `Cookie`.

{"item_id":3}
```

/// check

Notice that the value your function received (and returned) is `3`, as a Python `int`, not a string `"3"`.

So, with that type declaration, **FastAPI** gives you automatic request <dfn title="converting the string that comes from an HTTP request into Python data">"parsing"</dfn>.

///

## Data validation { #data-validation }

 *
 * <p>This class provides methods for:
 * <ul>
 * <li>Converting SuggestItem to Map (for OpenSearch indexing)</li>
 * <li>Parsing Map back to SuggestItem (from OpenSearch documents)</li>
 * <li>Creating updated source maps (for document updates)</li>
 * <li>Converting SuggestItem to JSON string</li>
 * </ul>
 */
public final class SuggestItemSerializer {

  public void testBigToDouble() {
    for (BigInteger b : ALL_BIGINTEGER_CANDIDATES) {
      if (b.doubleValue() != DoubleUtils.bigToDouble(b)) {
        failFormat(
            "Converting %s to double: expected doubleValue %s but got bigToDouble %s",
            b, b.doubleValue(), DoubleUtils.bigToDouble(b));
      }
    }
  }

  public void testEnsureNonNegative() {

     * @param roles the array of roles associated with the search words
     * @param score the score associated with the search words
     * @param readingConverter the converter to use for converting readings
     * @param normalizer the normalizer to use for normalizing the search words
     * @param analyzer the analyzer to use for analyzing the search words

     */
    public RankFusionSearcher() {
        // Default constructor - name will be initialized lazily
    }

    /**
     * Returns the name of this searcher.
     * The name is derived from the class name by converting it to lowercase
     * and removing the "Searcher" suffix.
     *
     * @return the searcher name
     */
    public String getName() {
        if (name == null) {

import org.opensearch.search.SearchHit;

/**
 * Utility class for search engine operations and content formatting.
 * Provides helper methods for working with XContent builders, scrolling through search results,
 * and converting XContent objects to different output formats.
 */
public final class SearchEngineUtil {

    private static final Logger logger = LogManager.getLogger(SearchEngineUtil.class);

    /**

    In this case, it's a list of `Item` dataclasses.

6. Here we are returning a dictionary that contains `items` which is a list of dataclasses.

    FastAPI is still capable of <dfn title="converting the data to a format that can be transmitted">serializing</dfn> the data to JSON.

7. Here the `response_model` is using a type annotation of a list of `Author` dataclasses.

    // ----------------/
    // - Constructors -/
    // ----------------/

    /**
     * Creates a new InputLocation from an API model InputLocation.
     * This constructor is used for converting between the API model and the compat model.
     *
     * @param location the API model InputLocation to convert from
     */
    public InputLocation(org.apache.maven.api.model.InputLocation location) {

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import org.jspecify.annotations.Nullable;

/**
 * Abstract {@link Hasher} that handles converting primitives to bytes using a scratch {@code
 * ByteBuffer} and streams all bytes to a sink to compute the hash.
 *
 * @author Colin Decker
 */
abstract class AbstractByteHasher extends AbstractHasher {