public Class<? extends AccessTokenProvider> getAccessTokenProviderClass(Configuration config) {
    return config.getClass(
        configPrefix + ACCESS_TOKEN_PROVIDER_IMPL_SUFFIX, null, AccessTokenProvider.class);
  }
public Class < ? extends AccessTokenProvider > getAccessTokenProviderClass ( Configuration config ) { return config . getClass ( configPrefix + ACCESS_TOKEN_PROVIDER_IMPL_SUFFIX , null , AccessTokenProvider . class ) ; }
Get the class that implements the AccessTokenProvider, from Hadoop {@link Configuration}.

@param config Hadoop {@link Configuration}
@return the class object of the class that implements the AccessTokenProvider, null if there
are no such classes.