SVG Writer Adding Space

When using the sample but changing the layer direction to bottom->top it becomes apparent that there is a large chunk of extra space generated in the svg. The height properity of the SVG is almost double the height of the contained data.

<svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" width="79.79687309265" height="480.87498474121" id="svg2" version="1.1"> <g transform="translate(79.7968730926514,250.437492370605)"> ... </g> </svg>

Removing the hard coded height and width and setting the 2nd part of the translate to 0 in the svg fixes the issue for me.

        Graph graph = new Graph();
        graph.AddEdge("47", "58");
        graph.AddEdge("70", "71");

        var subgraph = new Subgraph("subgraph1");
        graph.RootSubgraph.AddSubgraph(subgraph);
        subgraph.AddNode(graph.FindNode("47"));
        subgraph.AddNode(graph.FindNode("58"));

        var subgraph2 = new Subgraph("subgraph2");
        subgraph2.Attr.Color = Color.Black;
        subgraph2.Attr.FillColor = Color.Yellow;
        subgraph2.AddNode(graph.FindNode("70"));
        subgraph2.AddNode(graph.FindNode("71"));
        subgraph.AddSubgraph(subgraph2);
        graph.AddEdge("58", subgraph2.Id);
        graph.Attr.LayerDirection = LayerDirection.BT;

        var gr = new GraphRenderer(graph);            
        gr.CalculateLayout();

        using (var stream = File.Create(Path.Combine(Directory.GetCurrentDirectory(), @"example.svg")))
        {
            var writer = new SvgGraphWriter(stream, graph)
            {
                BlackAndWhite = false,
                AllowedToWriteUri = true,                   
            };
            writer.Write();               
        }

Start with the sample code in the issue, especially GraphRenderer.CalculateLayout and SvgGraphWriter.Write, and reproduce the output with LayerDirection.BT. Compare the SVG bounds and transform with the contained graph; done means the generated SVG does not include the reported excess vertical space.