EnumMapAccumulator::toImmutableMap);
  }

  private static class EnumMapAccumulator<K extends Enum<K>, V> {
    private final BinaryOperator<V> mergeFunction;
    @CheckForNull private EnumMap<K, V> map = null;

    EnumMapAccumulator(BinaryOperator<V> mergeFunction) {
      this.mergeFunction = mergeFunction;
    }

    void put(K key, V value) {
      if (map == null) {

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.Tables.AbstractCell;
import java.util.ArrayList;
import java.util.List;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.function.Supplier;
import java.util.stream.Collector;
import org.checkerframework.checker.nullness.qual.Nullable;

  private static class EnumMapAccumulator<K extends Enum<K>, V> {
    private final BinaryOperator<V> mergeFunction;
    @CheckForNull private EnumMap<K, V> map = null;

    EnumMapAccumulator(BinaryOperator<V> mergeFunction) {
      this.mergeFunction = mergeFunction;
    }

    void put(K key, V value) {
      if (map == null) {

    BinaryOperator<@Nullable Integer> mergeFunction = (v1, v2) -> null;
    Collector<Cell<String, String, Integer>, ?, Table<String, String, Integer>> collector =
        TableCollectors.toTable(
            Cell::getRowKey,
            Cell::getColumnKey,
            Cell::getValue,
            (BinaryOperator<Integer>) mergeFunction,
            HashBasedTable::create);

import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.SortedMap;
import java.util.SortedSet;
import java.util.function.BinaryOperator;
import java.util.stream.Collector;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Provides static methods that involve a {@code Table}.
 *

import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Map;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.stream.Collector;
import java.util.stream.Collectors;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**

import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.util.Arrays;
import java.util.Collection;
import java.util.Comparator;
import java.util.Map;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.stream.Collector;
import java.util.stream.Collectors;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**

import java.io.ObjectInputStream;
import java.io.Serializable;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Spliterator;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.stream.Collector;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Comparator;
import java.util.Iterator;
import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.stream.Collector;
import java.util.stream.Collectors;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**

import java.util.EnumMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Spliterator;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.stream.Collector;
import java.util.stream.Collectors;
import org.checkerframework.checker.nullness.qual.Nullable;

/**