public function save( $post_id ) {

		if ( ! llms_verify_nonce( 'lifterlms_meta_nonce', 'lifterlms_save_data' ) ) {
			return;
		}

		$actions = array(
			'llms_process_refund' => 'save_refund',
			'llms_record_txn'     => 'save_transaction',
			'llms_resend_receipt' => 'resend_receipt',
		);

		foreach ( $actions as $action => $method ) {
			$action = llms_filter_input( INPUT_POST, $action );
			if ( $action ) {
				$this->$method( $post_id );
				break;
			}
		}

	}