public Function<UserRef, String> getDisplayTextFunc() {
            return displayTextFunc;
        }
Displays the first non-null value in this order:
<p>displayName</p>
<p>SubjectId</p>
<p>UUID surrounded in curly braces</p>
<p></p>
<p>This displayType is equivalent to calling {@link UserRef#toDisplayString()}</p>
stroom-util-shared/src/main/java/stroom/util/shared/UserRef.java