private transient E[] enumConstants;
  private transient int[] counts;
  private transient int distinctElements;
  private transient long size;

  /** Creates an empty {@code EnumMultiset}. */
  private EnumMultiset(Class<E> type) {
    this.type = type;
    checkArgument(type.isEnum());
    this.enumConstants = type.getEnumConstants();
    this.counts = new int[enumConstants.length];
  }