code: function mirrorPlacement (placement, delimiter) {
    return executeMirrorFunction(placement, (first, second) => {
      return [mirror[first], second]
    }, delimiter)
  }
docs: ---
  category: utilities/layout
  ---
  
  Given a string or array of one or two placement values, mirrors the placement
  vertically or horizontally based on the first value.
  
  Examples
  ```js
  mirrorPlacement('top start') // input
  ['bottom', 'start'] // output
  
  mirrorPlacement('top start', ' ') // input
  'bottom start' //output
  ```
  
  @param {string|Array} placement - a string of the form '<value> <value>' or array [<value>, <value>]
  @param {string} delimiter - when provided, a value with which the result array will be joined
  @returns {string|Array} - an array of values or, if the delimiter was supplied, a string of
  delimiter separated values