code: def _xml(self, prefix=""):
      s = "<svg "
      s += 'id="%s" ' % self._id
      s += self._viewport.xml
      s += self._transform.xml
      s += "\n"
      for item in self._items:
          s += item._xml(prefix=prefix + "    ") + "\n"
      s += "</svg>\n"
      return s
  
file_path: vispy/vispy/util/svg/svg.py
imports: from .group import Group
  from .viewport import Viewport
label_desc: Use image node_id 5 for calling the SVG obj's underlying member method code with example usage: obj._xml(prefix) and returns: s