Builder<E> combine(Builder<E> other) {
      if (hashTable != null) {
        for (int i = 0; i < other.size; ++i) {
          // requireNonNull is safe because the first `size` elements are non-null.
          add((E) requireNonNull(other.contents[i]));
        }
      } else {
        addAll(other.contents, other.size);
      }
      return this;
    }

    /**

   * {@link TreeSet} or the {@link Map#keySet} of an {@code IdentityHashMap}.
   *
   * <p><b>Note:</b> The returned view performs slightly better when {@code set1} is the smaller of
   * the two sets. If you have reason to believe one of your sets will generally be smaller than the
   * other, pass it first. Unfortunately, since this method sets the generic type of the returned

    public Builder<E> addAll(Iterator<? extends E> elements) {
      super.addAll(elements);
      return this;
    }

    @CanIgnoreReturnValue
    Builder<E> combine(Builder<E> other) {
      addAll(other.contents, other.size);
      return this;
    }

    /**
     * Returns a newly-created {@code ImmutableList} based on the contents of the {@code Builder}.
     */
    @Override

  public void testPuttingTheSameKeyTwiceThrowsOnBuild() {
    Builder<String, Integer> builder =
        new Builder<String, Integer>()
            .put("one", 1)
            .put("one", 1); // throwing on this line might be better but it's too late to change

    try {
      builder.buildOrThrow();
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  public void testBuildKeepingLast_allowsOverwrite() {

      }
      if (object instanceof MapDifference) {
        MapDifference<?, ?> other = (MapDifference<?, ?>) object;
        return entriesOnlyOnLeft().equals(other.entriesOnlyOnLeft())
            && entriesOnlyOnRight().equals(other.entriesOnlyOnRight())
            && entriesInCommon().equals(other.entriesInCommon())
            && entriesDiffering().equals(other.entriesDiffering());
      }
      return false;
    }

    @Override

    }

    @CanIgnoreReturnValue
    Builder<K, V> combine(Builder<K, V> other) {
      checkNotNull(other);
      ensureCapacity(this.size + other.size);
      System.arraycopy(
          other.alternatingKeysAndValues,
          0,
          this.alternatingKeysAndValues,
          this.size * 2,
          other.size * 2);
      this.size += other.size;
      return this;
    }

*   Added a distributed runtime using GRPC
*   Move skflow to `contrib/learn`
*   Better linear optimizer in `contrib/linear_optimizer`
*   Random forest implementation in `contrib/tensor_forest`
*   CTC loss and decoders in `contrib/ctc`
*   Basic support for `half` data type
*   Better support for loading user ops (see examples in `contrib/`)
*   Allow use of (non-blocking) Eigen threadpool with