* @param errorMessageTemplate a template for the exception message should the check fail. The
   *     message is formed by replacing each {@code %s} placeholder in the template with an
   *     argument. These are matched by position - the first {@code %s} gets {@code
   *     errorMessageArgs[0]}, etc. Unmatched arguments will be appended to the formatted message in
   *     square braces. Unmatched placeholders will be left as-is.

   * equivalent to RegularImmutableSet, save that instead of having a hash table containing the
   * elements directly and null for empty positions, we store indices of the keys in the hash table,
   * and ABSENT for empty positions.  We then look up the keys in alternatingKeysAndValues.
   *
   * (The index actually stored is the index of the key in alternatingKeysAndValues, which is

  private void addToCache(K key, V value) {
    addToCache(new CacheEntry<K, V>(key, value));
  }

  private void addToCache(CacheEntry<K, V> entry) {
    // Slide new entry into first cache position. Drop previous entry in second cache position.
    cacheEntry2 = cacheEntry1;
    cacheEntry1 = entry;
  }

  private static final class CacheEntry<K, V> {
    final K key;
    final V value;

      stackWithLastReturnedElementAtTop.pop();
      stackWithLastReturnedElementAtTop.push(e);
    }

    /**
     * Moves the given element from its current position in {@link #nextElements} to the top of the
     * stack so that it is returned by the next call to {@link Iterator#next()}. If the element is
     * not in {@link #nextElements}, this method throws an {@link UnknownElementException}.

   * returned by {@code get(rowKeyList().get(rowIndex), columnKeyList().get(columnIndex))}, but this
   * method runs more quickly.
   *
   * @param rowIndex position of the row key in {@link #rowKeyList()}
   * @param columnIndex position of the row key in {@link #columnKeyList()}
   * @return the value with the specified row and column

     * The ordering here is important: if we deleted the key entry and then the value entry,
     * the key entry's prev or next pointer might point to the dead value entry, and when we
     * put the new entry in the key entry's position in iteration order, it might invalidate
     * the linked list.
     */

    if (oldEntryForValue != null) {
      delete(oldEntryForValue);
    }

    if (oldEntryForKey != null) {

    for (int i = start; i < end; i++) {
      if (array[i] == target) {
        return i;
      }
    }
    return -1;
  }

  /**
   * Returns the start position of the first occurrence of the specified {@code target} within
   * {@code array}, or {@code -1} if there is no such occurrence.
   *

   * Returns the element at the specified position in this fluent iterable.
   *
   * <p><b>{@code Stream} equivalent:</b> {@code stream.skip(position).findFirst().get()} (but note
   * that this throws different exception types, and throws an exception if {@code null} would be
   * returned).
   *
   * @param position position of the element to return
   * @return the element at the specified position in this fluent iterable

   * returned by {@code get(rowKeyList().get(rowIndex), columnKeyList().get(columnIndex))}, but this
   * method runs more quickly.
   *
   * @param rowIndex position of the row key in {@link #rowKeyList()}
   * @param columnIndex position of the row key in {@link #columnKeyList()}
   * @return the value with the specified row and column

  private static final LittleEndianBytes byteArray;

  /**
   * Load 8 bytes into long in a little endian manner, from the substring between position and
   * position + 8. The array must have at least 8 bytes from offset (inclusive).
   *
   * @param input the input bytes
   * @param offset the offset into the array at which to start
   * @return a long of a concatenated 8 bytes