wp-includes/php-ai-client/src/Files/DTO/File.php:217Gets the MIME type of the file as a string.
string public function getMimeType(): string { return (string) $this->mimeType; }Introduced in 0.1.0. Unchanged from 7.0.4 through 7.1.0.
Signature, return type and hooks compared across 2 parsed releases.
src/wp-includes/php-ai-client/src/Files/DTO/File.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.