Element_Type_Manager::register_defaults()

	protected function register_defaults() {
		foreach ( $this->default_element_types as $slug => $element_type_class_name ) {
			$this->register( $slug, $element_type_class_name );
		}

		/**
		 * Fires when the default element types have been registered.
		 *
		 * This action should be used to register custom element types.
		 *
		 * @since 1.0.0
		 *
		 * @param Element_Type_Manager $element_types Element type manager instance.
		 */
		do_action( "{$this->get_prefix()}register_element_types", $this );
	}