Single-lever mixer tap

SketchSystems.spec

Single-lever mixer tap
  Closed*
    flip lever -> Open
  Open
    flip lever -> Closed
    Hot
      turn tap -> Cold
    Cold
      turn tap -> Hot

SketchSystems_prototype.js

function render(model){
  let current_state_name = model.active_states[0].name;
  return $("h1",
           {style: {color: "darkBlue"}},
           `The tap is: ${current_state_name}`
          );
}