* The easiest way to pin a host is turn on pinning with a broken configuration and read the
 * expected configuration when the connection fails. Be sure to do this on a trusted network, and
 * without man-in-the-middle tools like [Charles][charles] or [Fiddler][fiddler].
 *
 * For example, to pin `https://publicobject.com`, start with a broken configuration:
 *
 * ```java
 * String hostname = "publicobject.com";

  /** Helper to manually escape a 7-bit ascii character */
  private String escapeAscii(char c) {
    Preconditions.checkArgument(c < 128);
    String hex = "0123456789ABCDEF";
    return "%" + hex.charAt((c >> 4) & 0xf) + hex.charAt(c & 0xf);
  }

 * the License.
 */

package com.google.common.cache;

import org.jspecify.annotations.NullUnmarked;

/**
 * Utility {@link Weigher} implementations intended for use in testing.
 *
 * @author Charles Fry
 */
@NullUnmarked
public final class TestingWeighers {

  /** Returns a {@link Weigher} that returns the given {@code constant} for every request. */
  static Weigher<Object, Object> constantWeigher(int constant) {

 *     if any key is acceptable
 * @param <V> the most general type of values this listener can listen for; for example {@code
 *     Object} if any key is acceptable
 * @author Charles Fry
 * @since 10.0
 */
@GwtCompatible
@FunctionalInterface
public interface RemovalListener<K, V> {
  /**
   * Notifies the listener that a removal occurred at some point in the past.
   *

        for (int i = 0; i < version.length(); i++) {
            char character = version.charAt(i);
            int c = character;
            if (Character.isHighSurrogate(character)) {
                // read the next character as a low surrogate and combine into a single int
                try {
                    char low = version.charAt(i + 1);
                    char[] both = {character, low};

        }
      }
    }
    if (ipString.charAt(0) == IPV6_DELIMITER && ipString.charAt(1) != IPV6_DELIMITER) {
      return null; // ^: requires ^::
    }
    if (ipString.charAt(ipString.length() - 1) == IPV6_DELIMITER
        && ipString.charAt(ipString.length() - 2) != IPV6_DELIMITER) {
      return null; // :$ requires ::$
    }

      char[] chars = randomChars(rand, rand.nextInt(63) + 1);
      CharMatcher m = SmallCharMatcher.from(bitSet(chars), new String(chars));
      checkExactMatches(m, chars);
    }
  }

  static void checkExactMatches(CharMatcher m, char[] chars) {
    Set<Character> positive = Sets.newHashSetWithExpectedSize(chars.length);
    for (char c : chars) {
      positive.add(c);
    }

 Copyright <YEAR> <COPYRIGHT HOLDER>

 Permission is hereby granted, free  of charge, to any person obtaining
 a  copy  of this  software  and  associated  documentation files  (the
 "Software"), to  deal in  the Software without  restriction, including
 without limitation  the rights to  use, copy, modify,  merge, publish,
 distribute,  sublicense, and/or sell  copies of  the Software,  and to
 permit persons to whom the Software  is furnished to do so, subject to

import com.google.common.annotations.GwtIncompatible;
import java.util.concurrent.Executor;

/**
 * A collection of common removal listeners.
 *
 * @author Charles Fry
 * @since 10.0
 */
@GwtIncompatible
public final class RemovalListeners {

  private RemovalListeners() {}

  /**

import com.google.common.annotations.GwtCompatible;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.ConcurrentMap;

/**
 * The reason why a cached entry was removed.
 *
 * @author Charles Fry
 * @since 10.0
 */
@GwtCompatible
public enum RemovalCause {
  /**
   * The entry was manually removed by the user. This can result from the user invoking {@link