final String expectedFailMessage = "testing checked exception";
whenNew(MyClass.class).withNoArguments().thenThrow(new IOException(expectedFailMessage));
try {
tested.throwExceptionAndWrapInRunTimeWhenInvoction();
fail("Should throw a checked Exception!");
} catch (RuntimeException e) {
assertTrue(e.getCause() instanceof IOException);
assertEquals(expectedFailMessage, e.getMessage());
}