code: private Map findProviders() {
          Map providers = getContainer().getComponentDescriptorMap(Provider.class.getName());
          if (providers == null) {
              throw new Error("No providers discovered");
          }
  
          Set keys = providers.keySet();
          Map found = null;
  
          for (Iterator iter = keys.iterator(); iter.hasNext();) {
              String key = (String)iter.next();
  
              Provider provider;
  
              try {
                  provider = (Provider) getContainer().lookup(Provider.class.getName(), key);
              }
              catch (Exception e) {
                  log.warn("Failed to lookup provider for key: {}", key, e);
                  continue;
              }
  
              if (provider != null) {
                  if (found == null) {
                      found = new HashMap();
                  }
  
                  found.put(key, provider);
              }
          }
  
          return found;
      }
docs: Find any providers which are available in the container.