erd.mark.should == 4.5
erd.should have(2).vertices
erd.should have(1).edges
+
+ erd.vertices[0].neighbours.should include(erd.vertices[1])
+ erd.vertices[1].neighbours.should include(erd.vertices[0])
end
it "reads and creates a box with a self-loop"
end # #initialize
end
-end
\ No newline at end of file
+end