public Set<MapperConfig> load(InputStream inputStream) throws IOException {
        final PrometheusMappingConfig config = ymlMapper.readValue(inputStream, PrometheusMappingConfig.class);

        return config.metricMappingConfigs()
                .stream()
                .flatMap(this::mapMetric)
                .collect(Collectors.toSet());
    }
@Test
    void unknownType() {
        final Map<String, ImmutableList<Serializable>> config = Collections.singletonMap("metric_mappings",
                ImmutableList.of(
                        ImmutableMap.of(
                                "type", "unknown",
                                "metric_name", "test1",
                                "unknown_property", "foo.bar"
                        )));

        assertThatThrownBy(() -> configLoader.load(new ByteArrayInputStream(objectMapper.writeValueAsBytes(config))))
                .hasMessageContaining("Could not resolve type id 'unknown'");
    }