continue; // delete this duplicate
          }
          entry = new ImmutableMapEntry<>(key, value);
          duplicates.put(key, null);
        }
        newEntryArray[outI++] = entry;
      }
      entryArray = newEntryArray;
    }
    return new JdkBackedImmutableMap<>(delegateMap, asImmutableList(entryArray, n));
  }

  private final transient Map<K, V> delegateMap;