wp-includes/pomo/mo.php:74string|false public function export() { $tmp_fh = fopen( 'php://temp', 'r+' ); if ( ! $tmp_fh ) { return false; } $this->export_to_file_handle( $tmp_fh ); rewind( $tmp_fh ); return stream_get_contents( $tmp_fh ); }Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/pomo/mo.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.