docs: function SeriesDatasource(parameters, sources) {
      this.name = 'Series';
      this.sources = [];
      this.selectors = null;
  
      if (parameters instanceof Object && !(parameters instanceof Array)) {
  
          // load from object def
          for(var property in parameters) {
  
              if (property == 'sources') {
                  console.log('->sources');
                  var sources = parameters[property];
  
                  var new_sources = [];
                  for(var ds in sources) {
                      new_sources.push(ReportDatasource.create(sources[ds]));
                  }
  
                  this[property] = new_sources;
  
              } else if (property == 'parameters') {
                  this[property] = ReportParameter.create(parameters[property]);
              } else {
                  this[property] = parameters[property];
              }
          }
  
  
      } else {
          this.sources = sources;
          ReportDatasource.call(this, parameters);
      }
  
  }