public void decPrecedenceLevel(int val) throws InvalidQueryException {
      m_precedence -= val;
      if (m_precedence < 0) {
        throw new InvalidQueryException("Invalid query string: mismatched parentheses.");
      }
    }
Decrement the context precedence level.

@param val  how much the level is decremented by
@throws InvalidQueryException if the level is decremented below 0
ambari-server/src/main/java/org/apache/ambari/server/api/predicate/QueryParser.java