public String toJSON() {
		Graph g = new Graph(nodes, links, properties);
		ObjectMapper mapper = new ObjectMapper();
		mapper.setSerializationInclusion(Include.NON_NULL);
		try {
			return mapper.writeValueAsString(g);
		}
		catch (IOException e) {
			throw new IllegalStateException("Unexpected problem creating JSON from Graph", e);
		}
	}
Represents a Graph that Flo will display. A graph consists of simple nodes and links.

@author Andy Clement
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/job/dsl/Graph.java