old_contents: iD.ui.Sidebar = function(context) {
      var inspector = iD.ui.Inspector(context),
          current;
  
      function sidebar(selection) {
          var wrap = selection.append('div')
              .attr('class', 'inspector-hidden inspector-wrap fr');
  
          sidebar.hover = function(id) {
              if (!current && id) {
                  wrap.classed('inspector-hidden', false)
                      .classed('inspector-hover', true);
  
                  if (inspector.entityID() !== id || inspector.state() !== 'hover') {
                      inspector
                          .state('hover')
                          .entityID(id);
  
                      wrap.call(inspector);
                  }
              } else {
                  wrap.classed('inspector-hidden', true);
              }
          };
  
          sidebar.select = function(id, newFeature) {
              if (!current && id) {
                  wrap.classed('inspector-hidden', false)
                      .classed('inspector-hover', false);
  
                  if (inspector.entityID() !== id || inspector.state() !== 'select') {
                      inspector
                          .state('select')
                          .entityID(id)
                          .newFeature(newFeature);
  
                      wrap.call(inspector);
                  }
              } else {
                  wrap.classed('inspector-hidden', true);
              }
          };
  
          sidebar.show = function(component) {
              wrap.classed('inspector-hidden', true);
              current = selection.append('div')
                  .attr('class', 'sidebar-component')
                  .call(component);
          };
  
          sidebar.hide = function() {
              current.remove();
              current = null;
          };
      }
  
      return sidebar;
  };
  
new_contents: iD.ui.Sidebar = function(context) {
      var inspector = iD.ui.Inspector(context),
          current;
  
      function sidebar(selection) {
          var wrap = selection.append('div')
              .attr('class', 'inspector-hidden inspector-wrap fr');
  
          sidebar.hover = function(id) {
              if (!current && id) {
                  wrap.classed('inspector-hidden', false)
                      .classed('inspector-hover', true);
  
                  if (inspector.entityID() !== id || inspector.state() !== 'hover') {
                      inspector
                          .state('hover')
                          .entityID(id);
  
                      wrap.call(inspector);
                  }
              } else {
                  wrap.classed('inspector-hidden', true);
              }
          };
  
          sidebar.select = function(id, newFeature) {
              if (!current && id) {
                  wrap.classed('inspector-hidden', false)
                      .classed('inspector-hover', false);
  
                  if (inspector.entityID() !== id || inspector.state() !== 'select') {
                      inspector
                          .state('select')
                          .entityID(id)
                          .newFeature(newFeature);
  
                      wrap.call(inspector);
                  }
              } else {
                  wrap.classed('inspector-hidden', true);
              }
          };
  
          sidebar.show = function(component) {
              wrap.classed('inspector-hidden', true);
              current = selection.append('div')
                  .attr('class', 'sidebar-component')
                  .call(component);
          };
  
          sidebar.hide = function() {
              current.remove();
              current = null;
          };
      }
  
      sidebar.hover = function() {};
      sidebar.select = function() {};
      sidebar.show = function() {};
      sidebar.hide = function() {};
  
      return sidebar;
  };
  
subject: Fix tests