wp-includes/class-wp-image-editor.php:478Builds and returns proper suffix for file based on height and width.
string|false public function get_suffix() { if ( ! $this->get_size() ) { return false; } return "{$this->size['width']}x{$this->size['height']}"; }Introduced in 3.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-image-editor.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.