public static List<Expression> searchAggregationExpressions(Expression expression) {
    return new CollectAggregationExpressionsVisitor().process(expression, null);
  }
Search for built-in aggregate functions subexpressions.

@param expression expression to be searched
@return searched aggregate functions list
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/analyze/ExpressionAnalyzer.java