Map<String, String> childUrlRuleMap = newHashMap();
        childUrlRuleMap.put("//A", "href");
        childUrlRuleMap.put("//AREA", "href");
        childUrlRuleMap.put("//FRAME", "src");
        childUrlRuleMap.put("//IFRAME", "src");
        childUrlRuleMap.put("//IMG", "src");
        childUrlRuleMap.put("//LINK", "href");
        childUrlRuleMap.put("//SCRIPT", "src");

        final Map<String, String> childUrlRuleMap = newHashMap();
        childUrlRuleMap.put("//A", "href");
        childUrlRuleMap.put("//AREA", "href");
        childUrlRuleMap.put("//FRAME", "src");
        childUrlRuleMap.put("//IFRAME", "src");
        childUrlRuleMap.put("//IMG", "src");
        childUrlRuleMap.put("//LINK", "href");
        childUrlRuleMap.put("//SCRIPT", "src");

(pointer: coarse) {\n  .content-wrapper.iframe-mode .btn-iframe-close {\n    visibility: visible;\n  }\n}\n\n.content-wrapper.iframe-mode .navbar-nav {\n  overflow-y: auto;\n  width: 100%;\n}\n\n.content-wrapper.iframe-mode .navbar-nav .nav-link {\n  white-space: nowrap;\n}\n\n.content-wrapper.iframe-mode .navbar-nav .nav-item {\n  position: relative;\n}\n\n.content-wrapper.iframe-mode .navbar-nav .nav-item:hover .btn-iframe-close, .content-wrapper.iframe-mode .navbar-nav .nav-item:focus .btn-iframe-close...

ame-mode .btn-iframe-close{visibility:visible}}.content-wrapper.iframe-mode .navbar-nav{overflow-y:auto;width:100%}.content-wrapper.iframe-mode .navbar-nav .nav-link{white-space:nowrap}.content-wrapper.iframe-mode .navbar-nav .nav-item{position:relative}.content-wrapper.iframe-mode .navbar-nav .nav-item:focus .btn-iframe-close,.content-wrapper.iframe-mode .navbar-nav .nav-item:hover .btn-iframe-close{-webkit-animation-name:fadeIn;animation-name:fadeIn;-webkit-animation-duration:.3s;animation-dur...

        }

        // Write a frame.
        val length = (end - start).toInt()
        outputStream.write(outBytes, start.toInt(), length)

        // If the last frame was truncated, immediately close the connection.
        if (truncated) {
          socket.close()
        }
      } else {
        // read a frame
        val inFrame = InFrame(i, reader)
        reader.nextFrame(false, inFrame)

    writeMedium(frame, (headerBlock.size / 2).toInt() + paddingLength + 1)
    frame.writeByte(Http2.TYPE_HEADERS)
    frame.writeByte(FLAG_PADDED)
    frame.writeInt(expectedStreamId and 0x7fffffff)
    frame.writeByte(paddingLength)
    frame.write(headerBlock, headerBlock.size / 2)
    frame.write(padding)

    // Write the continuation frame, specifying no more frames are expected.

    while (buffer.size != 1024L) source.read(buffer, 1024)
    stream1.close(ErrorCode.CANCEL, null)
    val frame1 = peer.takeFrame()
    assertThat(frame1.type).isEqualTo(Http2.TYPE_HEADERS)
    val frame2 = peer.takeFrame()
    assertThat(frame2.type).isEqualTo(Http2.TYPE_RST_STREAM)
    val frame3 = peer.takeFrame()
    assertThat(frame3.type).isEqualTo(Http2.TYPE_RST_STREAM)
    assertThat(connection.readBytes.acknowledged).isEqualTo(0L)

Blocking APIs may be inefficient because you hold a thread idle while waiting on the network. Threads are expensive because they have both a memory overhead and a context-switching overhead.

#### Framed protocols

import okio.ByteString
import okio.Source
import okio.Timeout

/**
 * Reads HTTP/2 transport frames.
 *
 * This implementation assumes we do not send an increased [frame][Settings.getMaxFrameSize] to the
 * peer. Hence, we expect all frames to have a max length of [Http2.INITIAL_MAX_FRAME_SIZE].
 */
class Http2Reader(
  /** Creates a frame reader with max header table size of 4096. */
  private val source: BufferedSource,

      reason: String,
    )
  }

  /**
   * Process the next protocol frame.
   *
   *  * If it is a control frame this will result in a single call to [FrameCallback].
   *  * If it is a message frame this will result in a single call to [FrameCallback.onReadMessage].
   *    If the message spans multiple frames, each interleaved control frame will result in a
   *    corresponding call to [FrameCallback].
   */