EDIT

    private static final long serialVersionUID = 4307599154287181582L;

    public static final CdmPreference NewInstance(PreferenceSubject subject,

        return new CdmPreference(subject, predicate, value);

    }

        return new CdmPreference(subject, predicate, uuidListStr(value));

    }

        return new CdmPreference(subject, predicate, uuidListStr(Arrays.asList(value)));

    }

        return new CdmPreference(subject, predicate, value.toString());

    }

     * @param value

     * @return

     */

        return new CdmPreference(PreferenceSubject.NewDatabaseInstance(), predicate, value);

    }

     * @param value

     * @return

     */

        return new CdmPreference(PreferenceSubject.NewVaadinInstance(), predicate, value);

    }

     * @param value

     * @return

     */

        return new CdmPreference(PreferenceSubject.NewTaxEditorInstance(), predicate, value);

    }

      return new PrefKey(subject, predicate);

    }

        //for hibernate use only

        private PrefKey(){}

            this(subject.toString(), predicate.getKey());

        }

//      private PrefKey(PreferenceSubjectEnum subject, PreferencePredicate predicate){

	private CdmPreference(){}

		this.key = new PrefKey(subject, predicate);

		//TODO are null values allowed?		assert predicate != null : "value must not be null for preference";

		if (value != null && value.length() > 1023) {throw new IllegalArgumentException(