private int[] toIntArray(List<Integer> integers) {
			int[] result = new int[integers.size()];
			for (int i = 0; i < integers.size(); i++) {
				result[i] = integers.get(i);
			}
			return result;
		}
Construct a transition link, and possibly a new node if a suitable candidate does not already exist.
If a transition has already referenced a particular job in the same flow, reuse it. If not then
create a new node and link to it.

@param fromJobNodeId the id of the jobnode from which the transition is occurring
@param jobExitStatus the job exit status attached to this transition
@param targetJobName the transition target
@return the ID of the transition target node if a new node created, otherwise -1
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/job/dsl/JobSpecification.java