wp-includes/class-wp-customize-manager.php:6141Callback for sanitizing the external_header_video value.
$valuestringstring public function _sanitize_external_header_video( $value ) { return sanitize_url( trim( $value ) ); }Introduced in 4.7.1. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-customize-manager.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.