code: function offsetContainerProperty(offsetProperty, coordinates, diff) {
    return {
      ...coordinates,
      containerPosition: {
        ...coordinates.containerPosition,
        [offsetProperty]: coordinates.containerPosition[offsetProperty] + diff
      }
    };
  }
docs: Offsets the container
  @param {string} offsetProperty
  @param {Coordinates} coordinates
  @param {number} diff
  @returns {Coordinates}