### Question:
PropertyUtils { public static double getDouble(String key, double defaultVal) { String val = properties.getProperty(key.trim()); return val == null ? defaultVal : Double.parseDouble(val); } private  PropertyUtils(); static String getString(String key, String defaultVal); static String getString(String key); static int getInt(String key); static int getInt(String key, int defaultValue); static boolean getBoolean(String key); static Boolean getBoolean(String key, boolean defaultValue); static long getLong(String key, long defaultVal); static long getLong(String key); static double getDouble(String key, double defaultVal); T getEnum(String key, Class<T> type,
                                         T defaultValue);  }### Answer:
@Test public void testGetDouble() { double result = PropertyUtils.getDouble("abc", 5.0); assertEquals(5.0, result, 0); result = PropertyUtils.getDouble("cba", 5.0); assertEquals(3.1, result, 0.01); }