>From https://github.com/google/guava/wiki/GraphsExplained :
don't construct multiple elements that are equal to each other and expect them to be interchangeable. In particular, when adding such elements to a graph, you should create them once and store the reference if you will need to refer to those elements more than once during creation (rather than passing new MyMutableNode(id) to each add*() call). But I want a graph whose vertices are Resource from Jena. Because one resource may be met in a model multiple times, I expect that Jena will give me multiple instances of Resource with the same URL. What to do? How can I make a graph with Resource as vertices? Please help.
