checkNotNull(columnFunction, "columnFunction");
    checkNotNull(valueFunction, "valueFunction");
    checkNotNull(mergeFunction, "mergeFunction");

    /*
     * No mutable Table exactly matches the insertion order behavior of ImmutableTable.Builder, but
     * the Builder can't efficiently support merging of duplicate values.  Getting around this
     * requires some work.
     */

    return Collector.of(

import java.util.LinkedHashMap;
import java.util.Map;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * CompactLinkedHashMap is an implementation of a Map with insertion or LRU iteration order,
 * maintained with a doubly linked list through the entries. All optional operations (put and
 * remove) are supported. Null keys and values are supported.
 *

    copyIntoArray(other, 0);
    return other;
  }

  /** If this collection is backed by an array of its elements in insertion order, returns it. */
  @CheckForNull
  Object[] internalArray() {
    return null;
  }

  /**
   * If this collection is backed by an array of its elements in insertion order, returns the offset
   * where this collection's elements start.
   */
  int internalArrayStart() {

    return other;
  }

  /** If this collection is backed by an array of its elements in insertion order, returns it. */
  @CheckForNull
  @Nullable
  Object[] internalArray() {
    return null;
  }

  /**
   * If this collection is backed by an array of its elements in insertion order, returns the offset
   * where this collection's elements start.
   */
  int internalArrayStart() {

        // we need ObjectCountHashMap-backed contents, with its keys and values array in direct
        // insertion order
        contents = new ObjectCountHashMap<E>(contents);
        isLinkedHash = false;
      }
      buildInvoked = true;
      // contents is now ObjectCountHashMap, but still guaranteed to be in insertion order!
      return new RegularImmutableMultiset<E>(contents);
    }
  }

   */
  public long approximateElementCount() {
    long bitSize = bits.bitSize();
    long bitCount = bits.bitCount();

    /**
     * Each insertion is expected to reduce the # of clear bits by a factor of
     * `numHashFunctions/bitSize`. So, after n insertions, expected bitCount is `bitSize * (1 - (1 -
     * numHashFunctions/bitSize)^n)`. Solving that for n, and approximating `ln x` as `x - 1` when x

            ImmutableCollection.Builder.expandedCapacity(dedupedElements.length, minCapacity);
        dedupedElements = Arrays.copyOf(dedupedElements, newCapacity);
      }
    }

    /** Adds e to the insertion-order array of deduplicated elements. Calls ensureCapacity. */
    final void addDedupedElement(E e) {
      ensureCapacity(distinct + 1);
      dedupedElements[distinct++] = e;
    }

    /**

  /**
   * Returns an immutable set of the mappings in this map. The iteration order is specified by the
   * method used to create this map. Typically, this is insertion order.
   */
  @Override
  public ImmutableSet<Entry<K, V>> entrySet() {
    ImmutableSet<Entry<K, V>> result = entrySet;
    return (result == null) ? entrySet = createEntrySet() : result;
  }

import java.util.Spliterator;
import java.util.Spliterators;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * CompactLinkedHashMap is an implementation of a Map with insertion or LRU iteration order,
 * maintained with a doubly linked list through the entries. All optional operations (put and
 * remove) are supported. Null keys and values are supported.
 *

     * iterator's next element and pass it to the reference iterator through this method so it can
     * return the same element. This enables the assertion to pass and the reference iterator to
     * properly update its state.
     */
    void promoteToNext(E e) {
      if (nextElements.remove(e)) {
        nextElements.push(e);
      } else {