Returns PUML from the system as a SVG image. Requires plantuml library.

def write_svg(self):
        """
            Returns PUML from the system as a SVG image. Requires plantuml library.
        """
        import plantuml
        puml = self.write_puml()
        server = plantuml.PlantUML(url=self.url)
        svg = server.processes(puml)
        return svg