def write_file_index_page(self, first_html: str, final_html: str) -> None:
        """Write the file index page for this report."""
        index_file = self.write_index_page(
            self.index_pages["file"],
            first_html=first_html,
            final_html=final_html,
        )

        print_href = stdout_link(index_file, f"file://{os.path.abspath(index_file)}")
        self.coverage._message(f"Wrote HTML report to {print_href}")

        # Write the latest hashes for next time.
        self.incr.write()
Write the file index page for this report.
coverage/html.py