protected function write_csv_data( $data ) {
		$file = $this->get_file();

		// Add columns when finished.
		if ( 100 === $this->get_percent_complete() ) {
			$file = chr( 239 ) . chr( 187 ) . chr( 191 ) . $this->export_column_headers() . $file;
		}

		$file .= $data;
		@file_put_contents( $this->get_file_path(), $file ); // phpcs:ignore WordPress.VIP.FileSystemWritesDisallow.file_ops_file_put_contents, Generic.PHP.NoSilencedErrors.Discouraged, WordPress.WP.AlternativeFunctions.file_system_read_file_put_contents
	}