### Question:
Tracer { @SafeVarargs public static void setExceptionsToIgnore(Class<? extends Throwable>... ignoreClasses) { checkNotNull(ignoreClasses); Tracer.ignoreClasses = ignoreClasses; } protected  Tracer(); static void trace(Throwable e); static void trace(Throwable e, int count); static void traceContext(Throwable e, int count, Context context); static void traceEntry(Throwable e, Entry entry); static void traceEntry(Throwable e, int count, Entry entry); @SafeVarargs static void setExceptionsToTrace(Class<? extends Throwable>... traceClasses); static Class<? extends Throwable>[] getExceptionsToTrace(); @SafeVarargs static void setExceptionsToIgnore(Class<? extends Throwable>... ignoreClasses); static Class<? extends Throwable>[] getExceptionsToIgnore();  }### Answer:
@Test public void setExceptionsToIgnore() { Tracer.ignoreClasses = null; Tracer.traceClasses = null; Tracer.setExceptionsToIgnore(IgnoreException.class, IgnoreException2.class); Assert.assertFalse(Tracer.shouldTrace(new IgnoreException())); Assert.assertFalse(Tracer.shouldTrace(new IgnoreExceptionSub())); Assert.assertTrue(Tracer.shouldTrace(new Exception())); }
@Test(expected = IllegalArgumentException.class) public void testNull2() { Tracer.setExceptionsToIgnore(IgnoreException.class, null); }