dwg = svgwrite.Drawing(filename, (width, height), debug=True)
dwg.defs.add(dwg.style(_serialize_css_dict(css)))
args = {
    'insert': (0, 0),
    'size': ('100%', '100%'),
    'class': 'background'
}
r = svgwrite.shapes.Rect(**args)
dwg.add(r)