text: export function DiscardTags(difference) {
      return function(graph) {
          function discardTags(entity) {
              if (!_.isEmpty(entity.tags)) {
                  var tags = {};
                  _.each(entity.tags, function(v, k) {
                      if (v) tags[k] = v;
                  });
  
                  graph = graph.replace(entity.update({
                      tags: _.omit(tags, iD.data.discarded)
                  }));
              }
          }
  
          difference.modified().forEach(discardTags);
          difference.created().forEach(discardTags);
  
          return graph;
      };
  }
  