### Question:
WroFilter implements Filter { public void setRequestHandlerFactory(final RequestHandlerFactory requestHandlerFactory) { Validate.notNull(requestHandlerFactory); this.requestHandlerFactory = requestHandlerFactory; }  static boolean isPassedThroughyWroFilter(final HttpServletRequest request); final void init(final FilterConfig config); final void doFilter(final ServletRequest req, final ServletResponse res, final FilterChain chain); void setWroManagerFactory(final WroManagerFactory wroManagerFactory); final WroManagerFactory getWroManagerFactory(); void setRequestHandlerFactory(final RequestHandlerFactory requestHandlerFactory); void setWroConfigurationFactory(final ObjectFactory<WroConfiguration> wroConfigurationFactory); final WroConfiguration getConfiguration(); final void setConfiguration(final WroConfiguration config); void setEnable(final boolean enable); void destroy(); static final String ATTRIBUTE_PASSED_THROUGH_FILTER; }### Answer:
@Test(expected = NullPointerException.class) public void cannotAcceptNullRequestHandlerFactory() { victim.setRequestHandlerFactory(null); }