throw new AssertionError(incidentEdgeOrder.type());
    }

    return new DirectedGraphConnections<>(
        /* adjacentNodeValues= */ new HashMap<N, Object>(initialCapacity, INNER_LOAD_FACTOR),
        orderedNodeConnections,
        /* predecessorCount= */ 0,
        /* successorCount= */ 0);
  }

  static <N, V> DirectedGraphConnections<N, V> ofImmutable(