Replace all uses of six.with_metaclass with six.add_metaclass

iota/adapter/__init__.py

@@ -12,7 +12,7 @@
 
 from requests import Response, auth, codes, request
 from six import PY2, binary_type, iteritems, moves as compat, text_type, \
-    with_metaclass
+    add_metaclass
 
 from iota.exceptions import with_context
 from iota.json import JsonEncoder
@@ -139,7 +139,8 @@ def configure(cls, parsed):
         return cls(parsed)
 
 
-class BaseAdapter(with_metaclass(AdapterMeta)):
+@add_metaclass(AdapterMeta)
+class BaseAdapter(object):
     """
     Interface for IOTA API adapters.
 

iota/adapter/wrappers.py

@@ -5,7 +5,7 @@
 from abc import ABCMeta, abstractmethod as abstract_method
 from typing import Dict, Text
 
-from six import with_metaclass
+from six import add_metaclass
 
 from iota.adapter import AdapterSpec, BaseAdapter, resolve_adapter
 
@@ -14,7 +14,8 @@
 ]
 
 
-class BaseWrapper(with_metaclass(ABCMeta, BaseAdapter)):
+@add_metaclass(ABCMeta)
+class BaseWrapper(BaseAdapter):
     """
     Base functionality for "adapter wrappers", used to extend the
     functionality of IOTA adapters.

iota/api.py

@@ -4,7 +4,7 @@
 
 from typing import Dict, Iterable, Optional, Text
 
-from six import with_metaclass
+from six import add_metaclass
 
 from iota import AdapterSpec, Address, BundleHash, ProposedTransaction, Tag, \
     TransactionHash, TransactionTrytes, TryteString, TrytesCompatible
@@ -53,7 +53,8 @@ def __init__(cls, name, bases=None, attrs=None):
             cls.commands = commands
 
 
-class StrictIota(with_metaclass(ApiMeta)):
+@add_metaclass(ApiMeta)
+class StrictIota(object):
     """
     API to send HTTP requests for communicating with an IOTA node.
 

iota/bin/__init__.py

@@ -10,7 +10,7 @@
 from sys import exit
 from typing import Any, Optional, Text
 
-from six import text_type, with_metaclass
+from six import text_type, add_metaclass
 
 from iota import Iota, __version__
 from iota.crypto.types import Seed
@@ -20,7 +20,8 @@
 ]
 
 
-class IotaCommandLineApp(with_metaclass(ABCMeta)):
+@add_metaclass(ABCMeta)
+class IotaCommandLineApp(object):
     """
     Base functionality for a PyOTA-powered command-line application.
     """

iota/commands/__init__.py

@@ -88,7 +88,7 @@ def __init__(cls, what, bases=None, dict=None):
         command_registry[command] = cls
 
 @six.add_metaclass(CommandMeta)
-class BaseCommand():
+class BaseCommand(object):
   """
   An API command ready to send to the node.
   """

iota/json.py

@@ -6,10 +6,11 @@
 from json.encoder import JSONEncoder as BaseJsonEncoder
 from typing import Iterable, Mapping
 
-from six import with_metaclass
+from six import add_metaclass
 
 
-class JsonSerializable(with_metaclass(ABCMeta)):
+@add_metaclass(ABCMeta)
+class JsonSerializable(object):
     """
     Interface for classes that can be safely converted to JSON.
     """

test/api_test.py

@@ -5,7 +5,7 @@
 from abc import ABCMeta
 from unittest import TestCase
 
-from six import with_metaclass
+from six import add_metaclass
 
 from iota import InvalidCommand, StrictIota
 from iota.adapter import MockAdapter
@@ -150,5 +150,6 @@ class definition raises an exception.
         # This statement will raise an exception if the regression is
         # present; no assertions necessary.
         # noinspection PyUnusedLocal
-        class CustomClient(with_metaclass(ABCMeta)):
+        @add_metaclass(ABCMeta)
+        class CustomClient(object):
             client = StrictIota(MockAdapter())