code: private String extractAndConvertTaskType(Task task)
     {
        String activityType = (String) task.getCachedValue(m_activityTypeField);
        if (activityType == null)
        {
           activityType = "Resource Dependent";
        }
        else
        {
           if (ACTIVITY_TYPE_MAP.containsKey(activityType))
           {
              activityType = ACTIVITY_TYPE_MAP.get(activityType);
           }
        }
        return activityType;
     }
docs: Attempts to locate the activity type value extracted from an existing P6 schedule.
  If necessary converts to the form which can be used in the PMXML file.
  Returns "Resource Dependent" as the default value.
  
  @param task parent task
  @return activity type