* underlying (implementation specific) data structures to be shared.
 *
 * <p>The size of the data structure used by ArrayBasedCharEscaper and ArrayBasedUnicodeEscaper is
 * proportional to the highest valued character that has a replacement. For example a replacement
 * map containing the single character '{@literal \}u1000' will require approximately 16K of memory.

import com.google.common.annotations.GwtCompatible;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;

/**
 * An {@link ClusterException} is a data structure that allows for some code to "throw multiple
 * exceptions", or something close to it. The prototypical code that calls for this class is
 * presented below:
 *
 * <pre>

 * from uniform), and amortized since some operations can trigger a hash table resize.
 *
 * <p>As compared with {@link java.util.LinkedHashMap}, this structure places significantly reduced
 * load on the garbage collector by only using a constant number of internal objects.
 *
 * <p>This class should not be assumed to be universally superior to {@code

    };
  }

  /** Returns the children of the specified node. Must not contain null. */
  public abstract Iterable<T> children(T root);

  /**
   * Returns an unmodifiable iterable over the nodes in a tree structure, using pre-order traversal.
   * That is, each node's subtrees are traversed after the node itself is returned.
   *
   * <p>No guarantees are made about the behavior of the traversal when nodes change while iteration

 * contains information about the named HTML entities such as {@code &} and {@code "} while
 * {@link #escapeUnsafe} is overridden to handle general escaping of the form {@code &#NNNNN;}.
 *
 * <p>The size of the data structure used by {@link ArrayBasedUnicodeEscaper} is proportional to the
 * highest valued code point that requires escaping. For example a replacement map containing the

/**
 * A non-blocking queue which automatically evicts elements from the head of the queue when
 * attempting to add new elements onto the queue and it is full. This queue orders elements FIFO
 * (first-in-first-out). This data structure is logically equivalent to a circular buffer (i.e.,
 * cyclic buffer or ring buffer).
 *
 * <p>An evicting queue must be configured with a maximum size. Each time an element is added to a

import com.google.errorprone.annotations.Immutable;
import java.util.Comparator;
import java.util.Map;
import javax.annotation.CheckForNull;

/**
 * Used to represent the order of elements in a data structure that supports different options for
 * iteration order guarantees.
 *
 * <p>Example usage:
 *
 * <pre>{@code
 * MutableGraph<Integer> graph =

     */
    Set<Throwable> seenExceptionsLocal = seenExceptions;
    if (seenExceptionsLocal == null) {
      // TODO(cpovirk): Should we use a simpler (presumably cheaper) data structure?
      /*
       * Using weak references here could let us release exceptions earlier, but:
       *
       * 1. On Android, querying a WeakReference blocks if the GC is doing an otherwise-concurrent
       * pass.

import java.util.Map;
import javax.annotation.CheckForNull;

/**
 * A {@link MapIteratorCache} that adds additional caching. In addition to the caching provided by
 * {@link MapIteratorCache}, this structure caches values for the two most recently retrieved keys.
 *
 * @author James Sexton
 */
@ElementTypesAreNonnullByDefault
final class MapRetrievalCache<K, V> extends MapIteratorCache<K, V> {

/**
 * A non-blocking queue which automatically evicts elements from the head of the queue when
 * attempting to add new elements onto the queue and it is full. This queue orders elements FIFO
 * (first-in-first-out). This data structure is logically equivalent to a circular buffer (i.e.,
 * cyclic buffer or ring buffer).
 *
 * <p>An evicting queue must be configured with a maximum size. Each time an element is added to a