def run(self):
        """Sends extracted metadata in json format to stdout if stdout
        option is specified, assigns metadata dictionary to class_metadata
        variable otherwise.
        """
        if self.stdout:
            sys.stdout.write("extracted json data:\n" + json.dumps(
                self.metadata, default=to_str) + "\n")
        else:
            extract_dist.class_metadata = self.metadata
Sends extracted metadata in json format to stdout if stdout
        option is specified, assigns metadata dictionary to class_metadata
        variable otherwise.