@Test
void loadPrefixedConfigItems_testCommandLineOverrides() throws IOException, ConfigKeysNotRecognisedException {

    Builder builder = new Builder(new String[]{"-OPrefix1@TestConfig.FOO=100"});
    ConfigManager configManager = builder.loadConfigFromResourceOrFile(ImmutableList.of("src/test/prefixes-test-config-file.properties"), ImmutableSet.of(TestConfig.class, TestConfigDummy.class))
            .build();
    Config<TestConfig> testConfig = configManager.getConfig(TestConfig.class);
    assertThat(testConfig.getPrefixedConfigItems("Prefix1").getValue(TestConfig.FOO).asInt()).isEqualTo(100);
    assertThat(testConfig.getValue(TestConfig.FOO).asInt()).isEqualTo(1);
}