Empty graph check: Singleton graph check: [ 0 0 ] Star graph check with given root: [ 1 0 0 0 -0.104528 0.994522 -0.978148 -0.207912 0.309017 -0.951057 ] Star graph check with root found by topological sort: [ 0 0 1 0 -0.104528 0.994522 -0.978148 -0.207912 0.309017 -0.951057 ] Two minitrees without rootlevel: [ 0.642788 0.766044 2 0 -0.347296 1.96962 -0.34202 -0.939693 -1.87939 -0.68404 1 -1.73205 ] Two minitrees with rootlevel 10 and 20: [ 5.5 9.52628 12 0 -6 10.3923 -10.5 -18.1865 -22 0 11 -19.0526 ] Graph with just loops, triple edges and disconnected vertices: [ 1 0 -0.104528 0.994522 -0.209057 1.98904 -0.978148 -0.207912 0.309017 -0.951057 ] Checking proper error handling: Giving negative root. Giving negative rootlevel.