### Question:
Report extends RuntimeException { public Report at(String name, LocalWorld world, int x, int y, int z) { String worldName = world == null ? "unknown (NULL) world" : world.getName(); return with("location of " + name, "(" + worldName + ") " + x + ", " + y + ", " + z); } private  Report(Throwable t); static final Report of(Throwable t); @Override String getMessage(); Report with(String name, String value); Report at(String name, LocalWorld world, int x, int y, int z);  }### Answer:
@Test public void at() { Report report = Report.of(new RuntimeException()).at("something", null, 4, 6, 7); assertTrue(report.getMessage().contains("4, 6, 7")); }