### Question:
Log4jPipedAppender implements Appender { public void setPipedOutputStream( PipedOutputStream pipedOutputStream ) { this.pipedOutputStream = pipedOutputStream; } Log4jPipedAppender(); void addFilter( Filter filter ); Filter getFilter(); void clearFilters(); void close(); void doAppend( LoggingEvent event ); void setName( String name ); String getName(); void setErrorHandler( ErrorHandler arg0 ); ErrorHandler getErrorHandler(); void setLayout( Layout layout ); Layout getLayout(); boolean requiresLayout(); PipedOutputStream getPipedOutputStream(); void setPipedOutputStream( PipedOutputStream pipedOutputStream ); void setFilter( Filter filter );  }### Answer:
@Test public void setPipedOutputStream() { PipedOutputStream pipedOutputStream = new PipedOutputStream(); log4jPipedAppender.setPipedOutputStream( pipedOutputStream ); assertThat( log4jPipedAppender.getPipedOutputStream(), is( pipedOutputStream ) ); }