* signatures.
 */
fun Buffer.isProbablyUtf8(): Boolean {
  try {
    val prefix = Buffer()
    val byteCount = size.coerceAtMost(64)
    copyTo(prefix, 0, byteCount)
    for (i in 0 until 16) {
      if (prefix.exhausted()) {
        break
      }
      val codePoint = prefix.readUtf8CodePoint()
      if (Character.isISOControl(codePoint) && !Character.isWhitespace(codePoint)) {
        return false

  return when {
    isMappedIpv4Address(address) -> address.sliceArray(12 until 16)
    else -> address
  }
}

/** Returns true for IPv6 addresses like `0000:0000:0000:0000:0000:ffff:XXXX:XXXX`. */
private fun isMappedIpv4Address(address: ByteArray): Boolean {
  if (address.size != 16) return false

  for (i in 0 until 10) {
    if (address[i] != 0.toByte()) return false
  }

        if (c < n) {
          if (delta == Int.MAX_VALUE) return false // Prevent overflow.
          delta++
        } else if (c == n) {
          var q = delta

          for (k in BASE until Int.MAX_VALUE step BASE) {
            val t =
              when {
                k <= bias -> TMIN
                k >= bias + TMAX -> TMAX
                else -> k - bias
              }

application-layer must block on writing I/O. We can't return from a write until we've pushed its bytes onto the socket. Otherwise, if the write fails we are unable to deliver its IOException to the application. We would have told the application layer that the write succeeded, but it didn't!

The application-layer can also do blocking reads. If the application asks to read and there's nothing available, we need to hold that thread until either the bytes arrive, the stream is closed, or a timeout elapses....

import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ExecutionException;

/**
 * A semi-persistent mapping from keys to values. Values are automatically loaded by the cache, and
 * are stored in the cache until either evicted or manually invalidated. The common way to build
 * instances is using {@link CacheBuilder}.
 *
 * <p>Implementations of this interface are expected to be thread-safe, and can be safely accessed

 * When making TLS connections with multiple [connection specs](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-connection-spec/), these are attempted in sequence until the TLS handshake succeeds.

### [Connections](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-connection/)

When you request a URL with OkHttp, here's what it does:

		"Default values for istioctl flags").Get()

	LoggingOptions = defaultLogOptions()

	// scope is for dev logging.  Warning: log levels are not set by --log_output_level until command is Run().
	Scope = log.RegisterScope("cli", "istioctl")
)

func defaultLogOptions() *log.Options {
	o := log.DefaultOptions()
	// Default to warning for everything; we usually don't want logs in istioctl

    private fun combine(
      cachedHeaders: Headers,
      networkHeaders: Headers,
    ): Headers {
      val result = Headers.Builder()

      for (index in 0 until cachedHeaders.size) {
        val fieldName = cachedHeaders.name(index)
        val value = cachedHeaders.value(index)
        if ("Warning".equals(fieldName, ignoreCase = true) && value.startsWith("1")) {

		internalByteBuffer.Put(&b)
		return
	}
}

// readAllInto reads from r and appends to b until an error or EOF and returns the data it read.
// A successful call returns err == nil, not err == EOF. Because readAllInto is
// defined to read from src until EOF, it does not treat an EOF from Read
// as an error to be reported.
func readAllInto(b []byte, r *wsutil.Reader, want int64) ([]byte, error) {

import javax.annotation.CheckForNull;

/**
 * A semi-persistent mapping from keys to values. Cache entries are manually added using {@link
 * #get(Object, Callable)} or {@link #put(Object, Object)}, and are stored in the cache until either
 * evicted or manually invalidated. The common way to build instances is using {@link CacheBuilder}.
 *
 * <p>Implementations of this interface are expected to be thread-safe, and can be safely accessed