def _growByEdge(mesh, growSet, exclude):
	""" Grow a set of verts along edges without any fanciness
	Args:
		mesh: The mesh object for the growth
		growSet: A set of Vertex objects to grow.
		exclude: A set of Vertex objects to exclude from
			the growth

	Returns:
		newGrowSet: the grown verts
		newExclude: the next set of verts to exclude
	"""
	grown = set()
	for vert in growSet:
		grown.update(mesh.adjacentVertsByEdge(vert))

	newgrown = grown - exclude
	newexclude = exclude | growSet

	return newgrown, newexclude