class StringIndex implements Index {

  private final Map<String, IntArrayList> index;

  /** Creates an index on the given AbstractStringColumn */
  public StringIndex(StringColumn column) {
    int sizeEstimate = Integer.min(1_000_000, column.size() / 100);
    Map<String, IntArrayList> tempMap = new HashMap<>(sizeEstimate);
    for (int i = 0; i < column.size(); i++) {
      String value = column.get(i);
      IntArrayList recordIds = tempMap.get(value);
      if (recordIds == null) {
        recordIds = new IntArrayList();
        recordIds.add(i);
        tempMap.put(value, recordIds);
      } else {
        recordIds.add(i);
      }
    }
    index = new HashMap<>(tempMap);
  }

  private static void addAllToSelection(IntArrayList tableKeys, Selection selection) {
    for (int i : tableKeys) {
      selection.add(i);
    }
  }

  /**
   * Returns a bitmap {@link Selection} containing row numbers of all cells matching the given int
   *
   * @param value This is a 'key' from the index perspective, meaning it is a value from the
   *     standpoint of the column
   */
  public Selection get(String value) {<FILL_FUNCTION_BODY>}
}

    Selection selection = new BitmapBackedSelection();
    IntArrayList list = index.get(value);
    if (list != null) {
      addAllToSelection(list, selection);
    }
    return selection;
  
<no_super_class>