presto-main/src/main/java/io/prestosql/util/GraphvizPrinter.java/GraphvizPrinter/visitSpatialJoin
class GraphvizPrinter:        @Override
        public Void visitSpatialJoin(SpatialJoinNode node, Void context)
        {
            printNode(node, node.getType().getJoinLabel(), node.getFilter().toString(), NODE_COLORS.get(NodeType.JOIN));

            node.getLeft().accept(this, context);
            node.getRight().accept(this, context);

            return null;
        }