presto-main/src/main/java/io/prestosql/util/GraphvizPrinter.java/GraphvizPrinter/printNode
class GraphvizPrinter:        private void printNode(PlanNode node, String label, String color)
        {
            String nodeId = idGenerator.getNodeId(node);
            label = escapeSpecialCharacters(label);
            output.append(nodeId)
                    .append(format("[label=\"{%s}\", style=\"rounded, filled\", shape=record, fillcolor=%s]", label, color))
                    .append(';')
                    .append('\n');
        }