Added y-related obstacle-hash exceptions
REFACTOR: Made adjustments to a few tests before moving forward
RED: test_correctness_of_verify_topology_19
GREEN: test_correctness_of_verify_topology_19
RED: test_correctness_of_verify_topology_20
GREEN: test_correctness_of_verify_topology_20
RED: test_correctness_of_verify_topology_21
GREEN: test_correctness_of_verify_topology_21