presto-main/src/main/java/io/prestosql/sql/analyzer/ExpressionTreeUtils.java/ExpressionTreeUtils/extractAggregateFunctions
class ExpressionTreeUtils:    static List<FunctionCall> extractAggregateFunctions(Iterable<? extends Node> nodes, Metadata metadata)
    {
        return extractExpressions(nodes, FunctionCall.class, function -> isAggregation(function, metadata));
    }