def do_execute(self):
        """
        The actual execution of the actor.

        :return: None if successful, otherwise error message
        :rtype: str
        """
        result = None
        data = self.input.payload
        pltdataset.line_plot(
            data,
            atts=self.resolve_option("attributes"),
            percent=float(self.resolve_option("percent")),
            seed=int(self.resolve_option("seed")),
            title=self.resolve_option("title"),
            outfile=self.resolve_option("outfile"),
            wait=bool(self.resolve_option("wait")))
        return result
The actual execution of the actor.

        :return: None if successful, otherwise error message
        :rtype: str