// Parse each header.
      for (i in 0 until responseHeaders.size) {
        if (!responseHeaders.name(i).equals(HEADER_WEB_SOCKET_EXTENSION, ignoreCase = true)) {
          continue // Not a header we're interested in.
        }
        val header = responseHeaders.value(i)

        // Parse each extension.
        var pos = 0
        while (pos < header.length) {

import org.codelibs.core.lang.StringUtil;

/**
 * Represents an HTTP request header with a name and value.
 * This class is used to encapsulate the header information for HTTP requests.
 * It provides methods to get and set the name and value of the header,
 * as well as a method to validate the header.
 *
 * <p>Example usage:</p>
 * <pre>
 *     RequestHeader header = new RequestHeader("Content-Type", "application/json");

    }

    /**
     * Writes no-cache headers to the response.
     *
     * @param response the stream response
     * @param responseData the response data
     */
    protected void writeNoCache(final StreamResponse response, final ResponseData responseData) {
        response.header("Pragma", "no-cache");
        response.header("Cache-Control", "no-cache");
        response.header("Expires", "Thu, 01 Dec 1994 16:00:00 GMT");

// getCanonicalHeaders generate a list of request headers with their values
func getCanonicalHeaders(signedHeaders http.Header) string {
	var headers []string
	vals := make(http.Header, len(signedHeaders))
	for k, vv := range signedHeaders {
		k = strings.ToLower(k)
		headers = append(headers, k)
		vals[k] = vv
	}
	sort.Strings(headers)

	var buf bytes.Buffer
	for _, k := range headers {
		buf.WriteString(k)
		buf.WriteByte(':')

    while (lines.peek() == null) {
      Java8Compatibility.clear(cbuf);
      // The default implementation of Reader#read(CharBuffer) allocates a
      // temporary char[], so we call Reader#read(char[], int, int) instead.
      int read = (reader != null) ? reader.read(buf, 0, buf.length) : readable.read(cbuf);
      if (read == -1) {
        lineBuf.finish();
        break;
      }

    if x_token != fake_secret_token:
        raise HTTPException(status_code=400, detail="Invalid X-Token header")
    if item_id not in fake_db:
        raise HTTPException(status_code=404, detail="Item not found")
    return fake_db[item_id]


@app.post("/items/", response_model=Item)
async def create_item(item: Item, x_token: Annotated[str, Header()]):
    if x_token != fake_secret_token:

    }

    /**
     * @param reader a reader object.
     * @param strict a strict object.
     * @return PersistedToolchains
     * @throws IOException IOException if any.
     * @throws XmlPullParserException XmlPullParserException if
     *         any.
     * @see XmlStreamReader
     */
    public PersistedToolchains read(Reader reader, boolean strict) throws IOException, XmlPullParserException {

    assertThat(loader.getLoadCount()).isEqualTo(expectedLoads);
    assertThat(loader.getReloadCount()).isEqualTo(expectedReloads);

    ticker.advance(1, MILLISECONDS);
    assertThat(cache.getUnchecked(0)).isEqualTo(1);
    assertThat(cache.getUnchecked(1)).isEqualTo(-1);
    assertThat(cache.getUnchecked(2)).isEqualTo(3);
    assertThat(loader.getLoadCount()).isEqualTo(expectedLoads);

	}

	// "x-amz-content-sha256" header value from the extracted result.
	extractedContentSha256 := extractedSignedHeaders.Get("x-amz-content-sha256")
	// "host" header value from the extracted result.
	extractedHost := extractedSignedHeaders.Get("host")
	//  "x-amz-date" header from the extracted result.
	extractedDate := extractedSignedHeaders.Get("x-amz-date")
	// extracted `expect` header.

import pytest
from fastapi import FastAPI, Header
from fastapi.testclient import TestClient
from pydantic import BaseModel, Field

app = FastAPI()

# =====================================================================================
# Without aliases


@app.get("/optional-str")
async def read_optional_str(p: Annotated[Optional[str], Header()] = None):
    return {"p": p}