### Question:
ReferenceField implements FieldType<String> { @Override public String getDefaultValue() { return null; } ReferenceField();  ReferenceField(final String scope); @Override Types getType(); String getScope(); boolean isScoped(); @Override String getDefaultValue(); @Override boolean hasDefaultValue(); @Override String convert(Object objValue); @Override JSONObject toJson();  }### Answer:
@Test public void testGetDefaultValue() { System.out.println("getDefaultValue"); assertNull(new ReferenceField().getDefaultValue()); assertNull(new ReferenceField("table").getDefaultValue()); }