*/
    Throwable failureCause() {
      checkState(
          state == FAILED,
          "failureCause() is only valid if the service has failed, service is %s",
          state);
      // requireNonNull is safe because the constructor requires a non-null cause with state=FAILED.
      return requireNonNull(failure);
    }
  }

      @SuppressWarnings("unchecked")
      K key = (K) stream.readObject();
      @SuppressWarnings("unchecked")
      V value = (V) stream.readObject();
      /*
       * requireNonNull is safe for a properly serialized multimap: We've already inserted a
       * collection for each key that we expect.
       */
      requireNonNull(map.get(key)).add(value);
    }
    setMap(map);
  }

<code>l.TryLock</code> (or <code>l.TryRLock</code>)
may be considered to be able to return false
even when the mutex <i>l</i> is unlocked.
</p>

<h3 id="once">Once</h3>

<p>
The <code>sync</code> package provides a safe mechanism for
initialization in the presence of multiple goroutines
through the use of the <code>Once</code> type.
Multiple threads can execute <code>once.Do(f)</code> for a particular <code>f</code>,

- SSE-C is hardly adopted by most widely used applications, applications prefer server to manage the keys via SSE-KMS or SSE-S3.
- MinIO recommends applications to use SSE-KMS, SSE-S3 for simpler, safer and robust encryption mechanism for replicated buckets.

## Explore Further

- [MinIO Bucket Replication Design](https://github.com/minio/minio/blob/master/docs/bucket/replication/DESIGN.md)

 *       they appear. Input data is never modified. {@link HashFunction} instances should always be
 *       stateless, and therefore thread-safe.
 *   <li><b>collision-averse:</b> while it can't be helped that a hash function will sometimes
 *       produce the same hash code for distinct inputs (a "collision"), every hash function strives

 * and {@link Key} objects, with configurable algorithms and character encodings.
 * </p>
 * <p>
 * <strong>Key Features:</strong>
 * </p>
 * <ul>
 * <li>Thread-safe cipher pooling using {@link ConcurrentLinkedQueue}</li>
 * <li>Configurable encryption algorithms (default: Blowfish)</li>
 * <li>Proper charset handling for key generation (UTF-8 by default)</li>

                byte[] uniBytes = Strings.getUNIBytes(original);
                String uniRoundTrip = Strings.fromUNIBytes(uniBytes, 0, uniBytes.length);

                // When - round trip through ASCII encoding (for ASCII-safe strings)
                if (original.chars().allMatch(c -> c < 128)) {
                    byte[] asciiBytes = Strings.getASCIIBytes(original);

		// constant across restarts.
		h := sha1.New()
		h.Write([]byte(pluginURL))
		bs := h.Sum(nil)
		resourceID += base64.RawURLEncoding.EncodeToString(bs)
	} else {
		// Check that the roleID is restricted to URL safe characters
		// (base64 URL encoding chars).
		if !validRoleIDRegex.MatchString(roleID) {
			return args, config.Errorf("Role ID must match the regexp `^[a-zA-Z0-9_-]+$`")
		}

		// Use the user provided ID here.

            return OptionalThing.of(key.toString());
        }
        return OptionalThing.empty();
    }

    /**
     * Escapes special characters in a value string for safe logging.
     *
     * @param action the string value to escape
     * @return the escaped string with tabs replaced by spaces
     */
    protected String escapeValue(final String action) {

    /**
     * Thread priority for crawler threads.
     * Defaults to normal thread priority.
     */
    protected int crawlerPriority = Thread.NORM_PRIORITY;

    /**
     * Thread-safe list of active data crawling threads.
     * Used to track and manage all currently running crawler threads.
     */