it('should not change edges where the original graph was acyclic', function () {
g.setEdge('a', 'b', {minlen: 2, weight: 3})
acyclic.run(g)
acyclic.undo(g)
expect(g.edge('a', 'b')).to.eql({minlen: 2, weight: 3})
expect(g.edges()).to.have.length(1)
})
it('should restore previosuly reversed edges', function () {
g.setEdge('a', 'b', {minlen: 2, weight: 3})
g.setEdge('b', 'a', {minlen: 3, weight: 4})
acyclic.run(g)
acyclic.undo(g)
expect(g.edge('a', 'b')).to.eql({minlen: 2, weight: 3})
expect(g.edge('b', 'a')).to.eql({minlen: 3, weight: 4})
expect(g.edges()).to.have.length(2)
})