@Override public Object retrieve(String field) { if (field == null) { return null; } else if (field.equals(ID)) { return getId(); } else if (field.equals(VERSION)) { return getVersion(); } else if (field.equals(PARENT)) { return getParent(); } else if (field.equals(CHILD)) { return getChild(); } else if (field.equals(DETAILS)) { return getDetails(); } else { if (_dynamicFields != null) { return _dynamicFields.get(field); } return null; } }