question: public void testBuffered ( ) { Instances icopy = new Instances ( m_Instances ) ; Instances result = null ; try { m_Filter . setInputFormat ( icopy ) ; } catch ( Exception ex ) { ex . printStackTrace ( ) ; fail ( "Exception thrown on setInputFormat(): \n" + ex . getMessage ( ) ) ; } try { result = Filter . useFilter ( icopy , m_Filter ) ; assertNotNull ( result ) ; } catch ( Exception ex ) { ex . printStackTrace ( ) ; fail ( "Exception thrown on useFilter(): \n" + ex . getMessage ( ) ) ; } StringWriter sw = new StringWriter ( 2000 ) ; sw . write ( result . toString ( ) ) ; assertTrue ( icopy . equalHeaders ( m_Instances ) ) ; assertEquals ( icopy . numInstances ( ) , m_Instances . numInstances ( ) ) ; Instances result2 = null ; try { m_Filter . setInputFormat ( icopy ) ; } catch ( Exception ex ) { ex . printStackTrace ( ) ; fail ( "Exception thrown on setInputFormat(): \n" + ex . getMessage ( ) ) ; } try { result2 = Filter . useFilter ( icopy , m_Filter ) ; assertNotNull ( result2 ) ; } catch ( Exception ex ) { ex . printStackTrace ( ) ; fail ( "Exception thrown on useFilter(): \n" + ex . getMessage ( ) ) ; } assertTrue ( icopy . equalHeaders ( m_Instances ) ) ; assertEquals ( icopy . numInstances ( ) , m_Instances . numInstances ( ) ) ; assertTrue ( result . equalHeaders ( result2 ) ) ; assertEquals ( result . numInstances ( ) , result2 . numInstances ( ) ) ; }
target:  Test buffered operation. Output instances are only collected after all instances are passed through