checkState((type == Type.SORTED) == (comparator != null));
  }

  /** Returns an instance which specifies that no ordering is guaranteed. */
  public static <S> ElementOrder<S> unordered() {
    return new ElementOrder<>(Type.UNORDERED, null);
  }

  /**
   * Returns an instance which specifies that ordering is guaranteed to be always be the same across

  /**
   * Specifies the order of iteration for the elements of {@link Network#nodes()}.
   *
   * <p>The default value is {@link ElementOrder#insertion() insertion order}.
   */
  public <N1 extends N> NetworkBuilder<N1, E> nodeOrder(ElementOrder<N1> nodeOrder) {
    NetworkBuilder<N1, E> newBuilder = cast();
    newBuilder.nodeOrder = checkNotNull(nodeOrder);
    return newBuilder;
  }

  /**

  public <N1 extends N, V1 extends V> ImmutableValueGraph.Builder<N1, V1> immutable() {
    ValueGraphBuilder<N1, V1> castBuilder = cast();
    return new ImmutableValueGraph.Builder<>(castBuilder);
  }

  /**
   * Specifies whether the graph will allow self-loops (edges that connect a node to itself).
   * Attempting to add a self-loop to a graph that does not allow them will throw an {@link
   * UnsupportedOperationException}.
   *

     */
    Source source() default Source.USER_PROPERTIES;

    /**
     * Specifies the type of the configuration property.
     *
     * @return the fully qualified class name of the property type, defaults to "java.lang.String"
     */
    String type() default "java.lang.String";

    /**
     * Specifies the default value of the configuration property.
     *

  <pluginGroups>
    <!-- pluginGroup
     | Specifies a further group identifier to use for plugin lookup.
    <pluginGroup>com.your.plugins</pluginGroup>
    -->
  </pluginGroups>

  <!-- TODO Since when can proxies be selected as depicted? -->
  <!-- proxies
   | This is a list of proxies which can be used on this machine to connect to the network.
   | Unless otherwise specified (by system property or command-line switch), the first proxy

	// Together with upload-id-marker, this parameter specifies the multipart upload
	// after which listing should begin.
	KeyMarker string

	// Together with key-marker, specifies the multipart upload after which listing
	// should begin. If key-marker is not specified, the upload-id-marker parameter
	// is ignored.
	UploadIDMarker string

	// When a list is truncated, this element specifies the value that should be

# Connects standard error to journal
StandardError=journal

# When a JVM receives a SIGTERM signal it exits with code 143
SuccessExitStatus=143

# Specifies the maximum file descriptor number that can be opened by this process
LimitNOFILE=${packaging.os.max.open.files}

# Specifies the maximum number of bytes of memory that may be locked into RAM
# Set to "infinity" if you use the 'bootstrap.mlockall: true' option

```

`--sftp=cipher-algos=...` specifies the allowed cipher algorithms. 
If unspecified then a sensible default is used.

Valid values: 
```
aes128-ctr
aes192-ctr
aes256-ctr
******@****.***
******@****.***
******@****.***
arcfour256
arcfour128
arcfour
aes128-cbc
3des-cbc
```

  }

  /**
   * Specifies the expected number of nodes in the graph.
   *
   * @throws IllegalArgumentException if {@code expectedNodeCount} is negative
   */
  @CanIgnoreReturnValue
  public GraphBuilder<N> expectedNodeCount(int expectedNodeCount) {
    this.expectedNodeCount = checkNonNegative(expectedNodeCount);
    return this;
  }

  /**

     * Number of results parameter for error page fallback.
     * Specifies how many results to display if redirection fails.
     */
    public String num;

    /**
     * Sort parameter for error page fallback.
     * Defines the sorting order if redirection fails.
     */
    public String sort;

    /**
     * Language parameter for error page fallback.
     * Specifies the language preference if redirection fails.
     */