diff --git a/lang/fr/gklearn/kernels/path_up_to_h.py b/lang/fr/gklearn/kernels/path_up_to_h.py
new file mode 100644
index 0000000..1c8b5e2
--- /dev/null
+++ b/lang/fr/gklearn/kernels/path_up_to_h.py
@@ -0,0 +1,603 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Created on Fri Apr 10 18:33:13 2020
+
+@author: ljia
+
+@references: 
+
+	[1] Liva Ralaivola, Sanjay J Swamidass, Hiroto Saigo, and Pierre 
+	Baldi. Graph kernels for chemical informatics. Neural networks, 
+	18(8):1093–1110, 2005.
+"""
+import sys
+from multiprocessing import Pool
+from tqdm import tqdm
+import numpy as np
+import networkx as nx
+from collections import Counter
+from functools import partial
+from gklearn.utils import SpecialLabel
+from gklearn.utils.parallel import parallel_gm, parallel_me
+from gklearn.kernels import GraphKernel
+from gklearn.utils import Trie
+
+
+class PathUpToH(GraphKernel): # @todo: add function for k_func == None
+	
+	def __init__(self, **kwargs):
+		GraphKernel.__init__(self)
+		self.__node_labels = kwargs.get('node_labels', [])
+		self.__edge_labels = kwargs.get('edge_labels', [])
+		self.__depth = int(kwargs.get('depth', 10))
+		self.__k_func = kwargs.get('k_func', 'MinMax')
+		self.__compute_method = kwargs.get('compute_method', 'trie')
+		self.__ds_infos = kwargs.get('ds_infos', {})
+
+
+	def _compute_gm_series(self):
+		self.__add_dummy_labels(self._graphs)
+		
+		from itertools import combinations_with_replacement
+		itr_kernel = combinations_with_replacement(range(0, len(self._graphs)), 2)	
+		if self._verbose >= 2:
+			iterator_ps = tqdm(range(0, len(self._graphs)), desc='getting paths', file=sys.stdout)
+			iterator_kernel = tqdm(itr_kernel, desc='calculating kernels', file=sys.stdout)
+		else:
+			iterator_ps = range(0, len(self._graphs))
+			iterator_kernel = itr_kernel
+			
+		gram_matrix = np.zeros((len(self._graphs), len(self._graphs)))
+
+		if self.__compute_method == 'trie':
+			all_paths = [self.__find_all_path_as_trie(self._graphs[i]) for i in iterator_ps]
+			for i, j in iterator_kernel:
+				kernel = self.__kernel_do_trie(all_paths[i], all_paths[j])
+				gram_matrix[i][j] = kernel
+				gram_matrix[j][i] = kernel
+		else:
+			all_paths = [self.__find_all_paths_until_length(self._graphs[i]) for i in iterator_ps]
+			for i, j in iterator_kernel:
+				kernel = self.__kernel_do_naive(all_paths[i], all_paths[j])
+				gram_matrix[i][j] = kernel
+				gram_matrix[j][i] = kernel
+				
+		return gram_matrix
+			
+			
+	def _compute_gm_imap_unordered(self):
+		self.__add_dummy_labels(self._graphs)
+		
+		# get all paths of all graphs before calculating kernels to save time,
+		# but this may cost a lot of memory for large datasets.
+		pool = Pool(self._n_jobs)
+		itr = zip(self._graphs, range(0, len(self._graphs)))
+		if len(self._graphs) < 100 * self._n_jobs:
+			chunksize = int(len(self._graphs) / self._n_jobs) + 1
+		else:
+			chunksize = 100
+		all_paths = [[] for _ in range(len(self._graphs))]
+		if self.__compute_method == 'trie' and self.__k_func is not None:
+			get_ps_fun = self._wrapper_find_all_path_as_trie
+		elif self.__compute_method != 'trie' and self.__k_func is not None:  
+			get_ps_fun = partial(self._wrapper_find_all_paths_until_length, True)  
+		else: 
+			get_ps_fun = partial(self._wrapper_find_all_paths_until_length, False)
+		if self._verbose >= 2:
+			iterator = tqdm(pool.imap_unordered(get_ps_fun, itr, chunksize),
+							desc='getting paths', file=sys.stdout)
+		else:
+			iterator = pool.imap_unordered(get_ps_fun, itr, chunksize)
+		for i, ps in iterator:
+			all_paths[i] = ps
+		pool.close()
+		pool.join()
+		
+		# compute Gram matrix.
+		gram_matrix = np.zeros((len(self._graphs), len(self._graphs)))
+	 
+		if self.__compute_method == 'trie' and self.__k_func is not None:
+			def init_worker(trie_toshare):
+				global G_trie
+				G_trie = trie_toshare
+			do_fun = self._wrapper_kernel_do_trie
+		elif self.__compute_method != 'trie' and self.__k_func is not None:
+			def init_worker(plist_toshare):
+				global G_plist
+				G_plist = plist_toshare
+			do_fun = self._wrapper_kernel_do_naive   
+		else:
+			def init_worker(plist_toshare):
+				global G_plist
+				G_plist = plist_toshare
+			do_fun = self.__wrapper_kernel_do_kernelless # @todo: what is this?  
+		parallel_gm(do_fun, gram_matrix, self._graphs, init_worker=init_worker, 
+					glbv=(all_paths,), n_jobs=self._n_jobs, verbose=self._verbose) 	
+			
+		return gram_matrix
+	
+	
+	def _compute_kernel_list_series(self, g1, g_list):
+		self.__add_dummy_labels(g_list + [g1])
+		
+		if self._verbose >= 2:
+			iterator_ps = tqdm(g_list, desc='getting paths', file=sys.stdout)
+			iterator_kernel = tqdm(range(len(g_list)), desc='calculating kernels', file=sys.stdout)
+		else:
+			iterator_ps = g_list
+			iterator_kernel = range(len(g_list))
+			
+		kernel_list = [None] * len(g_list)
+
+		if self.__compute_method == 'trie':
+			paths_g1 = self.__find_all_path_as_trie(g1)
+			paths_g_list = [self.__find_all_path_as_trie(g) for g in iterator_ps]
+			for i in iterator_kernel:
+				kernel = self.__kernel_do_trie(paths_g1, paths_g_list[i])
+				kernel_list[i] = kernel
+		else:
+			paths_g1 = self.__find_all_paths_until_length(g1)
+			paths_g_list = [self.__find_all_paths_until_length(g) for g in iterator_ps]
+			for i in iterator_kernel:
+				kernel = self.__kernel_do_naive(paths_g1, paths_g_list[i])
+				kernel_list[i] = kernel
+				
+		return kernel_list
+	
+	
+	def _compute_kernel_list_imap_unordered(self, g1, g_list):
+		self.__add_dummy_labels(g_list + [g1])
+		
+		# get all paths of all graphs before calculating kernels to save time,
+		# but this may cost a lot of memory for large datasets.
+		pool = Pool(self._n_jobs)
+		itr = zip(g_list, range(0, len(g_list)))
+		if len(g_list) < 100 * self._n_jobs:
+			chunksize = int(len(g_list) / self._n_jobs) + 1
+		else:
+			chunksize = 100
+		paths_g_list = [[] for _ in range(len(g_list))]
+		if self.__compute_method == 'trie' and self.__k_func is not None:
+			paths_g1 = self.__find_all_path_as_trie(g1)
+			get_ps_fun = self._wrapper_find_all_path_as_trie
+		elif self.__compute_method != 'trie' and self.__k_func is not None:
+			paths_g1 = self.__find_all_paths_until_length(g1) 
+			get_ps_fun = partial(self._wrapper_find_all_paths_until_length, True)  
+		else:
+			paths_g1 = self.__find_all_paths_until_length(g1)  
+			get_ps_fun = partial(self._wrapper_find_all_paths_until_length, False)
+		if self._verbose >= 2:
+			iterator = tqdm(pool.imap_unordered(get_ps_fun, itr, chunksize),
+							desc='getting paths', file=sys.stdout)
+		else:
+			iterator = pool.imap_unordered(get_ps_fun, itr, chunksize)
+		for i, ps in iterator:
+			paths_g_list[i] = ps
+		pool.close()
+		pool.join()
+		
+		# compute kernel list.
+		kernel_list = [None] * len(g_list)
+		
+		def init_worker(p1_toshare, plist_toshare):
+			global G_p1, G_plist
+			G_p1 = p1_toshare
+			G_plist = plist_toshare
+		do_fun = self._wrapper_kernel_list_do
+		def func_assign(result, var_to_assign):	
+			var_to_assign[result[0]] = result[1]
+		itr = range(len(g_list))
+		len_itr = len(g_list)
+		parallel_me(do_fun, func_assign, kernel_list, itr, len_itr=len_itr,
+			init_worker=init_worker, glbv=(paths_g1, paths_g_list), method='imap_unordered', n_jobs=self._n_jobs, itr_desc='calculating kernels', verbose=self._verbose)
+			 			
+		return kernel_list
+	
+	
+	def _wrapper_kernel_list_do(self, itr):
+		if self.__compute_method == 'trie' and self.__k_func is not None:
+			return itr, self.__kernel_do_trie(G_p1, G_plist[itr])
+		elif self.__compute_method != 'trie' and self.__k_func is not None:
+			return itr, self.__kernel_do_naive(G_p1, G_plist[itr])  
+		else:
+			return itr, self.__kernel_do_kernelless(G_p1, G_plist[itr])
+	
+	
+	def _compute_single_kernel_series(self, g1, g2):
+		self.__add_dummy_labels([g1] + [g2])
+		if self.__compute_method == 'trie':
+			paths_g1 = self.__find_all_path_as_trie(g1)
+			paths_g2 = self.__find_all_path_as_trie(g2)
+			kernel = self.__kernel_do_trie(paths_g1, paths_g2)
+		else:
+			paths_g1 = self.__find_all_paths_until_length(g1)
+			paths_g2 = self.__find_all_paths_until_length(g2)
+			kernel = self.__kernel_do_naive(paths_g1, paths_g2)
+		return kernel			
+
+	
+	def __kernel_do_trie(self, trie1, trie2):
+		"""Calculate path graph kernels up to depth d between 2 graphs using trie.
+	
+		Parameters
+		----------
+		trie1, trie2 : list
+			Tries that contains all paths in 2 graphs.
+		k_func : function
+			A kernel function applied using different notions of fingerprint 
+			similarity.
+	
+		Return
+		------
+		kernel : float
+			Path kernel up to h between 2 graphs.
+		"""
+		if self.__k_func == 'tanimoto':	  
+			# traverse all paths in graph1 and search them in graph2. Deep-first 
+			# search is applied.
+			def traverseTrie1t(root, trie2, setlist, pcurrent=[]):
+				for key, node in root['children'].items():
+					pcurrent.append(key)
+					if node['isEndOfWord']:					
+						setlist[1] += 1
+						count2 = trie2.searchWord(pcurrent)
+						if count2 != 0:
+							setlist[0] += 1
+					if node['children'] != {}:
+						traverseTrie1t(node, trie2, setlist, pcurrent)
+					else:
+						del pcurrent[-1]
+				if pcurrent != []:
+					del pcurrent[-1]
+					
+					
+			# traverse all paths in graph2 and find out those that are not in 
+			# graph1. Deep-first search is applied. 
+			def traverseTrie2t(root, trie1, setlist, pcurrent=[]):
+				for key, node in root['children'].items():
+					pcurrent.append(key)
+					if node['isEndOfWord']:
+			#					print(node['count'])
+						count1 = trie1.searchWord(pcurrent)
+						if count1 == 0:	
+							setlist[1] += 1
+					if node['children'] != {}:
+						traverseTrie2t(node, trie1, setlist, pcurrent)
+					else:
+						del pcurrent[-1]
+				if pcurrent != []:
+					del pcurrent[-1]
+			
+			setlist = [0, 0] # intersection and union of path sets of g1, g2.
+	#		print(trie1.root)
+	#		print(trie2.root)
+			traverseTrie1t(trie1.root, trie2, setlist)
+	#		print(setlist)
+			traverseTrie2t(trie2.root, trie1, setlist)
+	#		print(setlist)
+			kernel = setlist[0] / setlist[1]
+			
+		elif self.__k_func == 'MinMax': # MinMax kernel		  
+			# traverse all paths in graph1 and search them in graph2. Deep-first 
+			# search is applied.
+			def traverseTrie1m(root, trie2, sumlist, pcurrent=[]):
+				for key, node in root['children'].items():
+					pcurrent.append(key)
+					if node['isEndOfWord']:
+# 						print(node['count'])
+						count1 = node['count']
+						count2 = trie2.searchWord(pcurrent)
+						sumlist[0] += min(count1, count2)
+						sumlist[1] += max(count1, count2)
+					if node['children'] != {}:
+						traverseTrie1m(node, trie2, sumlist, pcurrent)
+					else:
+						del pcurrent[-1]
+				if pcurrent != []:
+					del pcurrent[-1]
+			
+			# traverse all paths in graph2 and find out those that are not in 
+			# graph1. Deep-first search is applied.				
+			def traverseTrie2m(root, trie1, sumlist, pcurrent=[]):
+				for key, node in root['children'].items():
+					pcurrent.append(key)
+					if node['isEndOfWord']:				   
+			#					print(node['count'])
+						count1 = trie1.searchWord(pcurrent)
+						if count1 == 0:	
+							sumlist[1] += node['count']
+					if node['children'] != {}:
+						traverseTrie2m(node, trie1, sumlist, pcurrent)
+					else:
+						del pcurrent[-1]
+				if pcurrent != []:
+					del pcurrent[-1]
+			
+			sumlist = [0, 0] # sum of mins and sum of maxs
+# 			print(trie1.root)
+# 			print(trie2.root)
+			traverseTrie1m(trie1.root, trie2, sumlist)
+# 			print(sumlist)
+			traverseTrie2m(trie2.root, trie1, sumlist)
+# 			print(sumlist)
+			kernel = sumlist[0] / sumlist[1]
+		else:
+			raise Exception('The given "k_func" cannot be recognized. Possible choices include: "tanimoto", "MinMax".')
+	
+		return kernel
+	
+	
+	def _wrapper_kernel_do_trie(self, itr):
+		i = itr[0]
+		j = itr[1]
+		return i, j, self.__kernel_do_trie(G_trie[i], G_trie[j])
+	
+	
+	def __kernel_do_naive(self, paths1, paths2):
+		"""Calculate path graph kernels up to depth d between 2 graphs naively.
+	
+		Parameters
+		----------
+		paths_list : list of list
+			List of list of paths in all graphs, where for unlabeled graphs, each 
+			path is represented by a list of nodes; while for labeled graphs, each 
+			path is represented by a string consists of labels of nodes and/or 
+			edges on that path.
+		k_func : function
+			A kernel function applied using different notions of fingerprint 
+			similarity.
+	
+		Return
+		------
+		kernel : float
+			Path kernel up to h between 2 graphs.
+		"""
+		all_paths = list(set(paths1 + paths2))
+	
+		if self.__k_func == 'tanimoto':
+			length_union = len(set(paths1 + paths2))
+			kernel = (len(set(paths1)) + len(set(paths2)) -
+					  length_union) / length_union
+	#		vector1 = [(1 if path in paths1 else 0) for path in all_paths]
+	#		vector2 = [(1 if path in paths2 else 0) for path in all_paths]
+	#		kernel_uv = np.dot(vector1, vector2)
+	#		kernel = kernel_uv / (len(set(paths1)) + len(set(paths2)) - kernel_uv)
+	
+		elif self.__k_func == 'MinMax':  # MinMax kernel
+			path_count1 = Counter(paths1)
+			path_count2 = Counter(paths2)
+			vector1 = [(path_count1[key] if (key in path_count1.keys()) else 0)
+					   for key in all_paths]
+			vector2 = [(path_count2[key] if (key in path_count2.keys()) else 0)
+					   for key in all_paths]
+			kernel = np.sum(np.minimum(vector1, vector2)) / \
+				np.sum(np.maximum(vector1, vector2))
+				
+		elif self.__k_func is None: # no sub-kernel used; compare paths directly.
+			path_count1 = Counter(paths1)
+			path_count2 = Counter(paths2)
+			vector1 = [(path_count1[key] if (key in path_count1.keys()) else 0)
+					   for key in all_paths]
+			vector2 = [(path_count2[key] if (key in path_count2.keys()) else 0)
+					   for key in all_paths]
+			kernel = np.dot(vector1, vector2)
+			
+		else:
+			raise Exception('The given "k_func" cannot be recognized. Possible choices include: "tanimoto", "MinMax" and None.')
+	
+		return kernel
+	
+	
+	def _wrapper_kernel_do_naive(self, itr):
+		i = itr[0]
+		j = itr[1]
+		return i, j, self.__kernel_do_naive(G_plist[i], G_plist[j])
+	
+	
+	def __find_all_path_as_trie(self, G):
+	#	all_path = find_all_paths_until_length(G, length, ds_attrs, 
+	#										   node_label=node_label,
+	#										   edge_label=edge_label)
+	#	ptrie = Trie()
+	#	for path in all_path:
+	#		ptrie.insertWord(path)
+		
+	#	ptrie = Trie()
+	#	path_l = [[n] for n in G.nodes]  # paths of length l
+	#	path_l_str = paths2labelseqs(path_l, G, ds_attrs, node_label, edge_label)
+	#	for p in path_l_str:
+	#		ptrie.insertWord(p)
+	#	for l in range(1, length + 1):
+	#		path_lplus1 = []
+	#		for path in path_l:
+	#			for neighbor in G[path[-1]]:
+	#				if neighbor not in path:
+	#					tmp = path + [neighbor]
+	##					if tmp[::-1] not in path_lplus1:
+	#					path_lplus1.append(tmp)
+	#		path_l = path_lplus1[:]
+	#		# consider labels
+	#		path_l_str = paths2labelseqs(path_l, G, ds_attrs, node_label, edge_label)
+	#		for p in path_l_str:
+	#			ptrie.insertWord(p)
+	#	
+	#	print(time.time() - time1)
+	#	print(ptrie.root)
+	#	print()
+				
+				
+		# traverse all paths up to length h in a graph and construct a trie with 
+		# them. Deep-first search is applied. Notice the reverse of each path is 
+		# also stored to the trie.			   
+		def traverseGraph(root, ptrie, G, pcurrent=[]):
+			if len(pcurrent) < self.__depth + 1:
+				for neighbor in G[root]:
+					if neighbor not in pcurrent:
+						pcurrent.append(neighbor)
+						plstr = self.__paths2labelseqs([pcurrent], G)
+						ptrie.insertWord(plstr[0])
+						traverseGraph(neighbor, ptrie, G, pcurrent)
+			del pcurrent[-1]
+	
+	
+		ptrie = Trie()
+		path_l = [[n] for n in G.nodes]  # paths of length l
+		path_l_str = self.__paths2labelseqs(path_l, G)
+		for p in path_l_str:
+			ptrie.insertWord(p)
+		for n in G.nodes:
+			traverseGraph(n, ptrie, G, pcurrent=[n])
+			
+			
+	#	def traverseGraph(root, all_paths, length, G, ds_attrs, node_label, edge_label,
+	#					  pcurrent=[]):
+	#		if len(pcurrent) < length + 1:
+	#			for neighbor in G[root]:
+	#				if neighbor not in pcurrent:
+	#					pcurrent.append(neighbor)
+	#					plstr = paths2labelseqs([pcurrent], G, ds_attrs, 
+	#											node_label, edge_label)
+	#					all_paths.append(pcurrent[:])
+	#					traverseGraph(neighbor, all_paths, length, G, ds_attrs, 
+	#								   node_label, edge_label, pcurrent)
+	#		del pcurrent[-1]
+	#
+	#
+	#	path_l = [[n] for n in G.nodes]  # paths of length l
+	#	all_paths = path_l[:]
+	#	path_l_str = paths2labelseqs(path_l, G, ds_attrs, node_label, edge_label)
+	##	for p in path_l_str:
+	##		ptrie.insertWord(p)
+	#	for n in G.nodes:
+	#		traverseGraph(n, all_paths, length, G, ds_attrs, node_label, edge_label, 
+	#					   pcurrent=[n])
+		
+	#	print(ptrie.root)
+		return ptrie
+	
+	
+	def _wrapper_find_all_path_as_trie(self, itr_item):
+		g = itr_item[0]
+		i = itr_item[1]
+		return i, self.__find_all_path_as_trie(g)
+	
+	
+	# @todo: (can be removed maybe)  this method find paths repetively, it could be faster.
+	def __find_all_paths_until_length(self, G, tolabelseqs=True):
+		"""Find all paths no longer than a certain maximum length in a graph. A 
+		recursive depth first search is applied.
+	
+		Parameters
+		----------
+		G : NetworkX graphs
+			The graph in which paths are searched.
+		length : integer
+			The maximum length of paths.
+		ds_attrs: dict
+			Dataset attributes.
+		node_label : string
+			Node attribute used as label. The default node label is atom.
+		edge_label : string
+			Edge attribute used as label. The default edge label is bond_type.
+	
+		Return
+		------
+		path : list
+			List of paths retrieved, where for unlabeled graphs, each path is 
+			represented by a list of nodes; while for labeled graphs, each path is 
+			represented by a list of strings consists of labels of nodes and/or 
+			edges on that path.
+		"""
+		# path_l = [tuple([n]) for n in G.nodes]  # paths of length l
+		# all_paths = path_l[:]
+		# for l in range(1, self.__depth + 1):
+		#	 path_l_new = []
+		#	 for path in path_l:
+		#		 for neighbor in G[path[-1]]:
+		#			 if len(path) < 2 or neighbor != path[-2]:
+		#				 tmp = path + (neighbor, )
+		#				 if tuple(tmp[::-1]) not in path_l_new:
+		#					 path_l_new.append(tuple(tmp))
+	
+		#	 all_paths += path_l_new
+		#	 path_l = path_l_new[:]
+	
+		path_l = [[n] for n in G.nodes]  # paths of length l
+		all_paths = [p.copy() for p in path_l]
+		for l in range(1, self.__depth + 1):
+			path_lplus1 = []
+			for path in path_l:
+				for neighbor in G[path[-1]]:
+					if neighbor not in path:
+						tmp = path + [neighbor]
+	#					if tmp[::-1] not in path_lplus1:
+						path_lplus1.append(tmp)
+	
+			all_paths += path_lplus1
+			path_l = [p.copy() for p in path_lplus1]
+	
+		# for i in range(0, self.__depth + 1):
+		#	 new_paths = find_all_paths(G, i)
+		#	 if new_paths == []:
+		#		 break
+		#	 all_paths.extend(new_paths)
+	
+		# consider labels
+	#	print(paths2labelseqs(all_paths, G, ds_attrs, node_label, edge_label))
+	#	print()
+		return (self.__paths2labelseqs(all_paths, G) if tolabelseqs else all_paths)
+			
+			
+	def _wrapper_find_all_paths_until_length(self, tolabelseqs, itr_item):
+		g = itr_item[0]
+		i = itr_item[1]
+		return i, self.__find_all_paths_until_length(g, tolabelseqs=tolabelseqs)
+	
+	
+	def __paths2labelseqs(self, plist, G):
+		if len(self.__node_labels) > 0:
+			if len(self.__edge_labels) > 0:
+				path_strs = []
+				for path in plist:
+					pths_tmp = []
+					for idx, node in enumerate(path[:-1]):
+						pths_tmp.append(tuple(G.nodes[node][nl] for nl in self.__node_labels))
+						pths_tmp.append(tuple(G[node][path[idx + 1]][el] for el in self.__edge_labels))
+					pths_tmp.append(tuple(G.nodes[path[-1]][nl] for nl in self.__node_labels))
+					path_strs.append(tuple(pths_tmp))
+			else:
+				path_strs = []
+				for path in plist:
+					pths_tmp = []
+					for node in path:
+						pths_tmp.append(tuple(G.nodes[node][nl] for nl in self.__node_labels))
+					path_strs.append(tuple(pths_tmp))
+			return path_strs
+		else:
+			if len(self.__edge_labels) > 0:
+				path_strs = []
+				for path in plist:
+					if len(path) == 1:
+						path_strs.append(tuple())
+					else:
+						pths_tmp = []
+						for idx, node in enumerate(path[:-1]):
+							pths_tmp.append(tuple(G[node][path[idx + 1]][el] for el in self.__edge_labels))
+						path_strs.append(tuple(pths_tmp))
+				return path_strs
+			else:
+				return [tuple(['0' for node in path]) for path in plist]
+	#			return [tuple([len(path)]) for path in all_paths]
+	
+	
+	def __add_dummy_labels(self, Gn):
+		if self.__k_func is not None:
+			if len(self.__node_labels) == 0 or (len(self.__node_labels) == 1 and self.__node_labels[0] == SpecialLabel.DUMMY):
+				for i in range(len(Gn)):
+					nx.set_node_attributes(Gn[i], '0', SpecialLabel.DUMMY)
+				self.__node_labels = [SpecialLabel.DUMMY]
+			if len(self.__edge_labels) == 0 or (len(self.__edge_labels) == 1 and self.__edge_labels[0] == SpecialLabel.DUMMY):
+				for i in range(len(Gn)):
+					nx.set_edge_attributes(Gn[i], '0', SpecialLabel.DUMMY)
+				self.__edge_labels = [SpecialLabel.DUMMY]
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