code: function (spaceIdentifier, deviceIdentifier, params) {
        var path;
        if (spaceIdentifier) {
          path = this.constructPath(constants.SPACES, spaceIdentifier, constants.DEVICES, deviceIdentifier);
          return this.Core.GET(path, params);
        } else {
          return this.rejectRequest('Bad Request: A space identifier is required.');
        }
      }
docs: Get all the devices for a space or a particular device identified by `deviceIdentifier`
  @param  {String|Integer}           spaceIdentifier  A Robin space identifier
  @param  {String|Integer|undefined} deviceIdentifier A Robin device identifier
  @param  {Object|undefined}         params           A querystring object
  @return {Function}                                  A Promise