Source
File: wp-admin/includes/class-custom-image-header.php
public function init() {
$page = add_theme_page( __( 'Header' ), __( '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 );
}
}