wp-includes/style-engine/class-wp-style-engine.php:428Util: Checks whether an incoming block style value is valid.
$style_valuestringbool protected static function is_valid_style_value( $style_value ) { return '0' === $style_value || ! empty( $style_value ); }Introduced in 6.1.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/style-engine/class-wp-style-engine.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.