Map<V, K> backwardDelegate = Maps.newHashMapWithExpectedSize(n);
    for (int i = 0; i < n; i++) {
      // requireNonNull is safe because the first `n` elements have been filled in.
      Entry<K, V> e = RegularImmutableMap.makeImmutable(requireNonNull(entryArray[i]));
      entryArray[i] = e;
      V oldValue = forwardDelegate.putIfAbsent(e.getKey(), e.getValue());
      if (oldValue != null) {

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.collect.ImmutableList.asImmutableList;
import static com.google.common.collect.RegularImmutableMap.makeImmutable;
import static java.util.Objects.requireNonNull;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.util.HashMap;