code: protected String getDefaultEditorUri(CmsRequestContext context, String resourceType, String userAgent) {
  
          SortedMap<Float, CmsWorkplaceEditorConfiguration> filteredEditors = filterEditorsForResourceType(resourceType);
          while (filteredEditors.size() > 0) {
              // get the configuration with the lowest key value from the map
              Float key = filteredEditors.firstKey();
              CmsWorkplaceEditorConfiguration conf = filteredEditors.get(key);
              // match the found configuration with the current users browser
              if (conf.matchesBrowser(userAgent)) {
                  return conf.getEditorUri();
              }
              filteredEditors.remove(key);
          }
          if (context == null) {
              // this is just so that all parameters are used, signature should be identical to getEditorUri(...)
              return null;
          }
          // no valid default editor found
          return null;
      }
docs: Returns the default editor URI for the current resource type.<p>
  
  @param context the request context
  @param resourceType the current resource type
  @param userAgent the user agent String that identifies the browser
  @return a valid default editor URI for the resource type or null, if no editor matches