@Test
  void queryMapKeysMustBeStrings() throws Exception {
    try {
      parseAndValidateMetadata(QueryMapTestInterface.class, "nonStringKeyQueryMap", Map.class);
      Fail.failBecauseExceptionWasNotThrown(IllegalStateException.class);
    } catch (final IllegalStateException ex) {
      assertThat(ex).hasMessage("QueryMap key must be a String: Integer");
    }
  }
Body type is only for the body param.
core/src/test/java/feign/DefaultContractTest.java