-test_voronoi_utility.py:
	-debugging problem with test_geometric_spanner_condition_Delaunay_triangulation_sphere_surface() function
	-the primary issue seems to have been point duplication in the test sphere coordinate set; appear to have alleviated this by moving boundaries away from 0 and pi limits (so that multiple coincident points are not generated at the poles of the sphere)
	-also, substantially increasing the stringency for coordinate matching in identify_node_based_on_coordinate(), as this also seems to have been problematic to some degree
	-the geometric spanner condition proper hasn't been tested yet, but this is a step in the right direction