code: public static Relationship getRelationshipBetween(final Node source,
  			final Node target, final RelationshipType relationshipType,
  			final Direction direction) {
  		for (Relationship relationship : source.getRelationships(
  				relationshipType, direction)) {
  			if (relationship.getEndNode().equals(target)) {
  				return relationship;
  			}
  		}
  
  		return null;
  	}
docs: Search for a relationship between two nodes
  
  @param source
  source node to loop through relationships
  @param target
  target node of the relationship
  @param relationshipType
  relationship type of the relation being searched
  @param direction
  direction of the relationship being searched
  @return relationship instance matching the passed arguments if existing<br>
  <b>null</b> - otherwise