@Test
void loadPrefixedConfigItems_singlePrefix_testSubConfigs() throws IOException, ConfigKeysNotRecognisedException {

    Builder builder = new Builder(new String[]{});
    ConfigManager configManager = builder.loadConfigFromResourceOrFile(ImmutableList.of("src/test/prefixes-test-config-file.properties"), ImmutableSet.of(TestConfig.class, TestConfigDummy.class))
            .build();
    Config<TestConfig.Colours> subTestConfig = configManager.getConfig(TestConfig.class).getSubConfig(TestConfig.Colours.class);
    assertThat(subTestConfig.getValue(Colours.BLUE).asInt()).isEqualTo(7);
    assertThat(subTestConfig.getPrefixedConfigItems("Prefix1").getValue(TestConfig.Colours.RED).asInt()).isEqualTo(8);
    assertThat(subTestConfig.getPrefixedConfigItems("Prefix1").getValue(TestConfig.Colours.GREEN).asInt()).isEqualTo(9);
}