wp-admin/includes/class-custom-image-header.php:75Sets up the hooks for the Custom Header admin page.
public function init() { $page = add_theme_page( _x( 'Header', 'custom image header' ), _x( 'Header', 'custom image header' ), 'edit_theme_options', 'custom-header', array( $this, 'admin_page' ) ); if ( ! $page ) { return; } add_action( "admin_print_scripts-{$page}", array( $this, 'js_includes' ) ); add_action( "admin_print_styles-{$page}", array( $this, 'css_includes' ) ); add_action( "admin_head-{$page}", array( $this, 'help' ) ); add_action( "admin_head-{$page}", array( $this, 'take_action' ), 50 ); add_action( "admin_head-{$page}", array( $this, 'js' ), 50 ); if ( $this->admin_header_callback ) { add_action( "admin_head-{$page}", $this->admin_header_callback, 51 ); } }Introduced in 2.1.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-admin/includes/class-custom-image-header.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.