docs: function toggleLayerFromSplitMaps(state, layer) {
    return state.splitMaps.map(settings => {
      const {layers} = settings;
      const newLayers = {
        ...layers,
        [layer.id]: generateLayerMetaForSplitViews(layer)
      };
  
      return {
        ...settings,
        layers: newLayers
      };
    });
  }