### Question:
SystemProperties { public String getOsVersion() { return getSystemProperty(OS_VERSION); }  String getOsName(); String getOsVersion(); String getOsArch(); List<String> getPath();  }### Answer:
@Test public void getOsVersion() { String original = System.getProperty("os.version"); System.setProperty("os.version", "10"); assertThat(systemProperties.getOsVersion()).isEqualTo("10"); System.setProperty("os.version", original); }