presto-main/src/main/java/io/prestosql/util/GraphvizPrinter.java/NodePrinter/visitTableWriter
class NodePrinter:        @Override
        public Void visitTableWriter(TableWriterNode node, Void context)
        {
            List<String> columns = new ArrayList<>();
            for (int i = 0; i < node.getColumnNames().size(); i++) {
                columns.add(node.getColumnNames().get(i) + " := " + node.getColumns().get(i));
            }
            printNode(node, format("TableWriter[%s]", Joiner.on(", ").join(columns)), NODE_COLORS.get(NodeType.TABLE_WRITER));
            return node.getSource().accept(this, context);
        }