/**
   * Specifies the expected number of edges in the network.
   *
   * @throws IllegalArgumentException if {@code expectedEdgeCount} is negative
   */
  @CanIgnoreReturnValue
  public NetworkBuilder<N, E> expectedEdgeCount(int expectedEdgeCount) {
    this.expectedEdgeCount = Optional.of(checkNonNegative(expectedEdgeCount));
    return this;
  }

  /**