protected synchronized T initialValue(ViewContext context) {
    return null;
  }
Initial value of user-local class. Value can be set either by initialValue() on first get() call,
or directly by calling set() method. Default initial value is null, it can be changed by overriding
this method.
@param context initial value usually based on user properties provided by View Context
@return initial value of user-local variable
contrib/views/utils/src/main/java/org/apache/ambari/view/utils/UserLocal.java