Interface CaptionCommandFactory

Functional Interface:
This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface public interface CaptionCommandFactory
Turns a space, a style and a caption into a concrete DrawCommand.

The captioned counterpart of DrawCommandFactory: it exists as its own type rather than as a wider version of that one so a shape's builder has no way to supply a caption.