def listener(obj, trait_name, old, new):

    listener.obj = obj
    listener.trait_name = trait_name
    listener.old = old
    listener.new = new

    return
Asserts that the matching is what we expect from the bipartite graph
dataset/ETHPy150Open enthought/envisage/envisage/tests/plugin_test_case.py/listener--crossover with--dataset/ETHPy150Open networkx/networkx/networkx/algorithms/bipartite/tests/test_matching.py/TestMatching.check_match