Test Guice can init all bounded servlets

gistfile1.java

import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

import com.google.inject.Binding;
import com.google.inject.Injector;
import com.google.inject.servlet.GuiceFilter;

...

    public static void assertInit(Injector injector) {
        GuiceFilter filter = injector.getInstance(GuiceFilter.class);
        FilterConfig filterConfig = mock(FilterConfig.class);
        ServletContext context = mock(ServletContext.class);
        when(filterConfig.getServletContext()).thenReturn(context);
        try {
            filter.init(filterConfig);
        } catch (ServletException e) {
            throw new RuntimeException(e);
        }
    }