question: public void testChaining ( ) throws Exception { BasicUserNameMapper mapper1 = new BasicUserNameMapper ( ) ; mapper1 . setMappings ( Collections . singletonMap ( "1" , "101" ) ) ; KerberosUserNameMapper mapper2 = new KerberosUserNameMapper ( ) ; mapper2 . setInstance ( INSTANCE ) ; mapper2 . setRealm ( REALM ) ; ChainedUserNameMapper mapper = create ( mapper1 , mapper2 ) ; assertEquals ( "101" + "/" + INSTANCE + "@" + REALM , mapper . map ( "1" ) ) ; assertEquals ( "2" + "/" + INSTANCE + "@" + REALM , mapper . map ( "2" ) ) ; assertEquals ( IgfsUtils . fixUserName ( null ) + "/" + INSTANCE + "@" + REALM , mapper . map ( null ) ) ; }
target:  Test actual chaining logic.