override fun ackSettings() {
      check(type == -1)
      this.type = Http2.TYPE_SETTINGS
      this.ack = true
    }

    override fun headers(
      inFinished: Boolean,
      streamId: Int,
      associatedStreamId: Int,
      headerBlock: List<Header>,
    ) {
      check(type == -1)
      this.type = Http2.TYPE_HEADERS
      this.inFinished = inFinished
      this.streamId = streamId

Symmetrically, interceptors can rewrite response headers and transform the response body. This is generally more dangerous than rewriting request headers because it may violate the webserver's expectations!

If you're in a tricky situation and prepared to deal with the consequences, rewriting response headers is a powerful way to work around problems. For example, you can fix a server's misconfigured `Cache-Control` response header to enable better response caching:

        if (headers != null) {
            headers.forEach(header -> callback.accept(header.getFirst(), header.getSecond()));
        }
    }

## Version 4.9.2

_2021-09-30_

 *  Fix: Don't include potentially-sensitive header values in `Headers.toString()` or exceptions.
    This applies to `Authorization`, `Cookie`, `Proxy-Authorization`, and `Set-Cookie` headers.
 *  Fix: Don't crash with an `InaccessibleObjectException` when running on JDK17+ with strong
    encapsulation enabled.

import java.io.IOException;
import java.io.Reader;
import java.util.Iterator;
import org.jspecify.annotations.Nullable;

/**
 * A {@link Reader} that concatenates multiple readers.
 *
 * @author Bin Zhu
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
final class MultiReader extends Reader {
  private final Iterator<? extends CharSource> it;
  private @Nullable Reader current;

    )

    val call = client.newCall(Request(server.url("/")))
    call.execute().use { response ->
      assertThat(response.headers["Content-Length"]).isNull()
      assertThat(response.body.source().readUtf8()).isEqualTo("Hello")
      assertThat(response.trailers()).isEqualTo(Headers.EMPTY)
    }
  }

  @Test
  fun cancelWhileReadingTrailersHttp1() {
    cancelWhileReadingTrailers(Protocol.HTTP_1_1)
  }

  }

  @Test
  fun headers() {
    var headers: Headers = headersOf("", "")
    headers = mapOf("" to "").toHeaders()
    val get: String? = headers[""]
    val date: Date? = headers.getDate("")
    val instant: Instant? = headers.getInstant("")
    val size: Int = headers.size
    val name: String = headers.name(0)
    val value: String = headers.value(0)
    val names: Set<String> = headers.names()

When writing request headers, use `header(name, value)` to set the only occurrence of `name` to `value`. If there are existing values, they will be removed before the new value is added. Use `addHeader(name, value)` to add a header without removing the headers already present.

      Request
        .Builder()
        .url(server.url("/"))
        .header("", "A")
        .build()
    }
  }

  @Test
  fun emptyResponseHeaderNameIsLenient() {
    val headers = Headers.Builder()
    addHeaderLenient(headers, ":A")
    server.enqueue(
      MockResponse(
        headers = headers.build(),
        body = "body",
      ),
    )

	public final fun addUnsafeNonAscii (Ljava/lang/String;Ljava/lang/String;)Lokhttp3/Headers$Builder;
	public final fun build ()Lokhttp3/Headers;
	public final fun get (Ljava/lang/String;)Ljava/lang/String;
	public final fun removeAll (Ljava/lang/String;)Lokhttp3/Headers$Builder;
	public final fun set (Ljava/lang/String;Ljava/lang/String;)Lokhttp3/Headers$Builder;