### Question:
LocalConfigurationService implements LocalConfiguration, Serializable { @Override public String get(final String key) { return rawDelegates .stream() .map(d -> read(d, plugin + "." + key)) .filter(Objects::nonNull) .findFirst() .orElseGet(() -> rawDelegates .stream() .map(d -> read(d, key)) .filter(Objects::nonNull) .findFirst() .orElse(null)); }  @Override String get(final String key); @Override Set<String> keys();  }### Answer:
@Test void nullDoesntFail() { assertNull(new LocalConfigurationService(singletonList(systemProperties), "LocalConfigurationServiceTest") .get("test.foo.missing")); }
@Test void readGlobal() { System.setProperty("test.foo.LocalConfigurationServiceTest", "1"); try { assertEquals("1", new LocalConfigurationService(singletonList(systemProperties), "LocalConfigurationServiceTest") .get("test.foo.LocalConfigurationServiceTest")); } finally { System.clearProperty("test.foo.LocalConfigurationServiceTest"); } }