presto-main/src/main/java/io/prestosql/sql/planner/iterative/rule/ExtractCommonPredicatesExpressionRewriter.java/Visitor/rewriteExpression
class Visitor:        @Override
        public Expression rewriteExpression(Expression node, NodeContext context, ExpressionTreeRewriter<NodeContext> treeRewriter)
        {
            if (context.isRootNode()) {
                return treeRewriter.rewrite(node, NodeContext.NOT_ROOT_NODE);
            }

            return null;
        }