def build_sub_O2(Graph):
	"""
		For each white node in Graph, we create a copy of Graph and perform O2 in that node.
		Return a list of the graphs obtained.
	"""

	White = Graph.white()
	sub_list = []

	for index, n in enumerate(White):
		temp_g = Graph.O2(n)
		temp_g.labeling(index+1)
		sub_list.append(temp_g)

	return(sub_list)