public <C extends Credentials, U extends CommonProfile> Auth client(final String pattern,
      final Client<C, U> client) {
    return client(pattern, config -> client);
  }
public <C extends Credentials, U extends CommonProfile> Auth client(final String pattern,
      final Client<C, U> client) {
    return client(pattern, config -> client);
  }
public < C extends Credentials , U extends CommonProfile > Auth client ( final String pattern , final Client < C , U > client ) { return client ( pattern , config -> client ) ; }
Add an auth client, like facebook, twitter, github, etc...Please note the require dependency
must be in the classpath.

@param pattern URL pattern to protect.
@param client Client to add.
@param <C> Credentials.
@param <U> CommonProfile.
@return This module.
Add an auth client like facebook twitter github etc ... Please note the require dependency must be in the classpath .