code: function (spaceIdentifier, params) {
      var path = this.constructPath(constants.SPACES, spaceIdentifier);
      return this.Core.GET(path, params);
    }
docs: Get all spaces or a particular space identified by `spaceIdentifier`
  @param  {String|Integer}   spaceIdentifier A Robin space identifier
  @param  {Object|undefined} params          A querystring object
  @return {Function}                         A promise