Write the mappings between vertex indices and labels(target vs. not) to a file.

        :param list targets: List of known targets.
        :param str output_path: Path to the output file.

def write_index_labels(self, targets, output_path):
        """Write the mappings between vertex indices and labels(target vs. not) to a file.

        :param list targets: List of known targets.
        :param str output_path: Path to the output file.
        """
        label_mappings = self.get_index_labels(targets)

        with open(output_path, "w") as file:
            for k, v in label_mappings.items():
                print(k, v, sep='\t', file=file)