code: function getMeasurements(startDate, endDate, params, callback) {
      params = params || {};
      if(!startDate && !endDate) {
        startDate = new Date();
        startDate.setHours(startDate.getHours() - 24);
        startDate = formatDate(startDate);
        endDate = new Date();
        endDate = formatDate(endDate);
      }
      params.startdate = startDate;
      params.endDate = endDate;
      core.callApi('/AirQualityService/v1.0/Measurements', params, callback);
    }
docs: Returns a list of measurements
  
  @memberof module:gbgcity/AirQuality
  @param {Date} startDate From when to get measurements
  @param {Date} endDate To when to get measurements
  @param {Object} [params] An object containing additional parameters.
  @param {Function} callback The function to call with results, function({Error} error, {Object} results)/
  @see http://data.goteborg.se/AirQualityService/v1.0/help/operations/GetLatestMeasurements