protected String rawExpression() {
    StringBuilder raw = new StringBuilder("actions=");
    if (actions != null) {
      int i = 0;
      for (Action action : actions) {
        if (i > 0) {
          raw.append(",");
        }
        raw.append(action != null ? action.toString() : "NULL");
        i++;
      }
    }
    return raw.toString();
  }
Check if two permission equals regardless of actions. It is useful when merging a new
permission with an existed permission which needs to check two permissions's fields.
@param obj instance
@return true if equals, false otherwise
hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/Permission.java