code: public static Collection<INimbusCredentialPlugin> getNimbusAutoCredPlugins(Map conf) {
          try {
              Set<INimbusCredentialPlugin> ret = new HashSet<INimbusCredentialPlugin>();
              Collection<String> clazzes = (Collection<String>) conf.get(Config.NIMBUS_AUTO_CRED_PLUGINS);
              if (clazzes != null) {
                  for (String clazz : clazzes) {
                      INimbusCredentialPlugin inst = (INimbusCredentialPlugin) Class.forName(clazz).newInstance();
                      inst.prepare(conf);
                      ret.add(inst);
                  }
              }
              return ret;
          } catch (Exception e) {
              throw new RuntimeException(e);
          }
      }
docs: Get all the Nimbus Auto cred plugins.
  
  @param conf nimbus configuration to use.
  @return nimbus auto credential plugins.