fetchData = function () {
      return $http(
        angular.extend({
            method : 'GET',
            url : self.parseUrl(self.urlTemplate || urlTemplate, lang)
          },
          $httpOptions)
      );
    }
@name parseUrl
@method

@description
Returns a parsed url template string and replaces given target lang
and part name it.

@param {string|function} urlTemplate - Either a string containing an url pattern (with
                                       '{part}' and '{lang}') or a function(part, lang)
                                       returning a string.
@param {string} targetLang - Language key for language to be used.
@return {string} Parsed url template string