public static void setUserProviderForTesting(Configuration conf,
    Class<? extends UserProvider> provider) {
    conf.set(USER_PROVIDER_CONF_KEY, provider.getName());
  }
Set the {@link UserProvider} in the given configuration that should be instantiated
@param conf     to update
@param provider class of the provider to set
hbase-common/src/main/java/org/apache/hadoop/hbase/security/UserProvider.java