code: function getSlide({ index, itemsPerSlide }, i = index) {
      if (!itemsPerSlide) {
          return;
      }
  
      return Math.ceil(i / itemsPerSlide);
  }
docs: Gets the slide for a given index.
  Defaults to the current index if none provided.
  
  @param {object} state The widget state.
  @param {number?} i the index to get the slide for.
  @return {number}