update( /*frame*/ ) {

		console.warn( 'Abstract function.' );

	}
The method can be implemented to update the node's internal state when it is used to render an object.
The {@link Node#updateType} property defines how often the update is executed.

@abstract
@param {NodeFrame} frame - A reference to the current node frame.
@return {?boolean} An optional bool that indicates whether the implementation actually performed an update or not (e.g. due to caching).