Bounds not correctly computed for texts and groups about svg HOT 5 OPEN

using Svg;

var document = new SvgDocument()
{
    Width = new SvgUnit(SvgUnitType.Inch, 10),
    Height = new SvgUnit(SvgUnitType.Inch, 10),
    FontSize = 15,
    FontFamily = "Sans-Serif",
};

var svgGroup = new SvgGroup();

float x = 100, y = 100;

var xLocation = new SvgUnitCollection();
var yLocation = new SvgUnitCollection();

xLocation.Add(x);
yLocation.Add(y);

var textBox = new SvgText
{
    X = xLocation,
    Y = yLocation
};

var lines = new List<string>()
{
    "This is",
    "a multiline",
    "test"
};

float offset = 0;

foreach (var line in lines)
{
    var unit = new SvgUnit(SvgUnitType.Em, offset);
    var yOffset = new SvgUnitCollection
    {
        unit
    };

    var textSpan = new SvgTextSpan
    {
        Text = line,
        Dy = yOffset,
        X = xLocation,
    };

    textBox.Children.Add(textSpan);
    offset += 1F;
}

textBox.AddStyle("fill", "black", 0);
textBox.AddStyle("font-size", "inherit", 0);

svgGroup.Children.Add(textBox);

var boundingBox = new SvgRectangle
{
    X = textBox.Bounds.X,
    Y = textBox.Bounds.Y,
    Width = textBox.Bounds.Width,
    Height = textBox.Bounds.Height
};

boundingBox.AddStyle("fill", "none", 0);
boundingBox.AddStyle("stroke", "black", 0);

svgGroup.Children.Add(boundingBox);

document.Children.Add(svgGroup);

var completePath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyPictures), "test.svg");

document.Write(completePath, false);