*/
interface TrailersSource {
  @Throws(IOException::class)
  fun peek(): Headers? = null

  @Throws(IOException::class)
  fun get(): Headers

  companion object {
    @JvmField
    val EMPTY: TrailersSource =
      object : TrailersSource {
        override fun peek() = Headers.EMPTY

        override fun get() = Headers.EMPTY
      }
  }

      headers.name(-1)
    }
    assertThat(headers.name(0)).isEqualTo("a")
    assertThat(headers.name(1)).isEqualTo("c")
    assertFailsWith<IndexOutOfBoundsException> {
      headers.name(2)
    }
  }

  @Test fun valueIndexesAreStrict() {
    val headers = headersOf("a", "b", "c", "d")
    assertFailsWith<IndexOutOfBoundsException> {
      headers.value(-1)
    }
    assertThat(headers.value(0)).isEqualTo("b")

    }

  fun assertHeader(
    name: String,
    vararg values: String?,
  ) = apply {
    assertThat(response!!.headers(name)).containsExactly(*values)
  }

  fun assertHeaders(headers: Headers) =
    apply {
      assertThat(response!!.headers).isEqualTo(headers)
    }

  fun assertBody(expectedBody: String) =
    apply {
      assertThat(body).isEqualTo(expectedBody)
    }

    }
  }
  return null
}

internal fun Headers.Builder.commonAdd(
  name: String,
  value: String,
) = apply {
  headersCheckName(name)
  headersCheckValue(value, name)
  commonAddLenient(name, value)
}

internal fun Headers.Builder.commonAddAll(headers: Headers) =
  apply {
    for (i in 0 until headers.size) {
      commonAddLenient(headers.name(i), headers.value(i))
    }
  }

    /**
     * Returns the subset of the headers in [requestHeaders] that impact the content of the
     * response's body.
     */
    private fun varyHeaders(
      requestHeaders: Headers,
      responseHeaders: Headers,
    ): Headers {
      val varyFields = responseHeaders.varyFields()
      if (varyFields.isEmpty()) return Headers.EMPTY

      val result = Headers.Builder()

    val recorded = server.takeRequest()
    assertThat(recorded.headers["Accept"]).isEqualTo("text/plain")
    assertThat(recorded.headers["Accept-Encoding"]).isEqualTo("gzip")
    assertThat(recorded.headers["Connection"]).isNull()
    assertThat(recorded.headers["User-Agent"]!!).matches(Regex("Jetty/.*"))
  }

    val authority = request.headers["Host"] // Has host and port.
    val fancyRequest =
      Request
        .Builder()
        .url("$scheme://$authority/")
        .headers(request.headers)
        .build()
    val fancyResponse =
      Response
        .Builder()
        .code(webSocketResponse.code)
        .message(webSocketResponse.message)
        .headers(webSocketResponse.headers)

      .build()
  }

  companion object {
    /** Combines cached headers with a network headers as defined by RFC 7234, 4.3.4. */
    private fun combine(
      cachedHeaders: Headers,
      networkHeaders: Headers,
    ): Headers {
      val result = Headers.Builder()

      for (index in 0 until cachedHeaders.size) {
        val fieldName = cachedHeaders.name(index)

        Map<String, List<String>> headers = new HashMap<>();
        headers.put("Content-Type", Arrays.asList("application/json"));
        headers.put("Content-Length", Arrays.asList("100"));

        response.setHeaders(headers);

        Map<String, List<String>> result = response.getHeaders();
        assertNotNull(result);
        // Headers should be stored in lowercase

        }
      }

      // There's another part. Parse its headers and return it.
      val headers = HeadersReader(source).readHeaders()
      val partSource = PartSource()
      currentPart = partSource
      return Part(headers, partSource.buffer())
    }

    /** A single part in the stream. It is an error to read this after calling [nextPart]. */