Add ability to GEDEnv to use pre-defined costs between node labels.

gklearn/utils/dataset.py

@@ -535,6 +535,16 @@ class Dataset(object):
 		dataset.set_labels(node_labels=node_labels, node_attrs=node_attrs, edge_labels=edge_labels, edge_attrs=edge_attrs)
 		# @todo: clean_labels and add other class members?
 		return dataset
+	
+	
+	def get_all_node_labels(self):
+		node_labels = []
+		for g in self.__graphs:
+			for n in g.nodes():
+				nl = tuple(g.nodes[n].items())
+				if nl not in node_labels:
+					node_labels.append(nl)
+		return node_labels
 		
 	
 	def __get_dataset_size(self):