}

    @CanIgnoreReturnValue
    Builder<K, V> combine(ImmutableSortedMap.Builder<K, V> other) {
      ensureCapacity(size + other.size);
      System.arraycopy(other.keys, 0, this.keys, this.size, other.size);
      System.arraycopy(other.values, 0, this.values, this.size, other.size);
      size += other.size;
      return this;
    }

    /**
     * Returns a newly-created immutable sorted map.
     *

      throw new UnsupportedOperationException("Not available on ImmutableSortedMap.Builder");
    }

    @Override
    Builder<K, V> combine(ImmutableMap.Builder<K, V> other) {
      super.combine(other);
      return this;
    }

    /**
     * Returns a newly-created immutable sorted map.
     *
     * <p>Prefer the equivalent method {@link #buildOrThrow()} to make it explicit that the method