### Question:
BooleanField implements FieldType<Boolean> { @Override public boolean hasDefaultValue() { return defaultValue != null; } BooleanField();  BooleanField(final Boolean defaultValue); @Override Types getType(); @Override Boolean getDefaultValue(); @Override boolean hasDefaultValue(); @Override Boolean convert(Object objValue); @Override JSONObject toJson();  }### Answer:
@Test public void testHasDefaultValue() { System.out.println("hasDefaultValue"); BooleanField instance = new BooleanField(); assertFalse(instance.hasDefaultValue()); instance = new BooleanField(true); assertTrue(instance.hasDefaultValue()); instance = new BooleanField(false); assertTrue(instance.hasDefaultValue()); }