### Question:
DoubleAccessor implements PropertyAccessor<Double> { @Override public String toString(Object object) { return object != null ? object.toString() : null; }  @Override Double fromBytes(Class targetClass, byte[] data); @Override byte[] toBytes(Object object); @Override String toString(Object object); @Override Double fromString(Class targetClass, String s); @Override Double getCopy(Object object); Double getInstance(Class<?> clazz);  }### Answer:
@Test public void testToStringObject() { Assert.assertNull(accessor.toString(null)); Double d1 = new Double(4.555); String s1 = d1.toString(); String s2 = accessor.toString(d1); Assert.assertTrue(s1.equals(s2)); }