docs: public static Matcher<Object> hasSingleFailureContaining(final String string) {
          return new BaseMatcher<Object>() {
              public boolean matches(Object item) {
                  return item.toString().contains(string) && failureCountIs(1).matches(item);
              }
  
              public void describeTo(Description description) {
                  description.appendText("has single failure containing " + string);
              }
          };
      }