The purpose of the test is to check that by calling the addEdge method on an existing
multiGraph object a new edge will be added to the graph. The method to be used is addNode(String id, Node node1, Node node2)
Input Specification
The possible values of the different categories for the method's inputs and environment are defined
in the following text file:
The combinations of the category values (generated with genpairs) to be used as input for the test cases
to be generated are presented in the following csv file: