### Question:
VerbosePageCacheTracer extends DefaultPageCacheTracer { @Override public void unmappedFile( File file ) { log.info( format( "Unmap file: '%s'.", file.getName() ) ); super.unmappedFile( file ); } VerbosePageCacheTracer( Log log, SystemNanoClock clock ); @Override void mappedFile( File file ); @Override void unmappedFile( File file ); @Override MajorFlushEvent beginCacheFlush(); @Override MajorFlushEvent beginFileFlush( PageSwapper swapper );  }### Answer:
@Test public void traceUnmapFile() { VerbosePageCacheTracer tracer = createTracer(); tracer.unmappedFile( new File( "unmapFile" ) ); logProvider.formattedMessageMatcher().assertContains( "Unmap file: 'unmapFile'." ); }