docs: function parseString (string, tmpIn, tmpOut) {
      var resultIn = null
      var resultOut = null
      var resultString = string.replace(placeHolderRegex, function (match) {
        switch (match) {
          case IN:
            resultIn = resultIn || tmpIn
            return resultIn
          case OUT:
            resultOut = resultOut || tmpOut
            return resultOut
          /* istanbul ignore next */
          default:
            throw new Error("Found '" + match + "'. Placeholder regex not consistent: " + JSON.stringify({
              IN: IN,
              OUT: OUT,
              match: match
            }))
        }
      })
  
      return {
        in: resultIn,
        out: resultOut,
        string: resultString
      }
    }