docs: def addDefaultShareID(store, shareID, priority):
      """
      Add a default share ID to C{store}, pointing to C{shareID} with a
      priority C{priority}.  The highest-priority share ID identifies the share
      that will be retrieved when a user does not explicitly provide a share ID
      in their URL (e.g. /host/users/username/).
  
      @param shareID: A share ID.
      @type shareID: C{unicode}
  
      @param priority: The priority of this default.  Higher means more
      important.
      @type priority: C{int}
      """
      _DefaultShareID(store=store, shareID=shareID, priority=priority)