public WithJsonPath(JsonPath jsonPath, Matcher<T> resultMatcher) {
        this.jsonPath = jsonPath;
        this.resultMatcher = resultMatcher;
    }
@Test
    public void shouldDescribeMismatchOfEvaluation() {
        Matcher<? super ReadContext> matcher = withJsonPath("expensive", equalTo(3));
        Description description = new StringDescription();
        matcher.describeMismatch(BOOKS_JSON, description);
        assertThat(description.toString(), containsString("expensive"));
        assertThat(description.toString(), containsString("<10>"));
    }