--- a/sat/plugins/plugin_xep_0261.py	Wed Jun 27 07:51:29 2018 +0200
+++ b/sat/plugins/plugin_xep_0261.py	Wed Jun 27 20:14:46 2018 +0200
@@ -20,6 +20,7 @@
 from sat.core.i18n import _
 from sat.core.constants import Const as C
 from sat.core.log import getLogger
+
 log = getLogger(__name__)
 from wokkel import disco, iwokkel
 from zope.interface import implements
@@ -32,7 +33,7 @@
     from wokkel.subprotocols import XMPPHandler
 
 
-NS_JINGLE_IBB = 'urn:xmpp:jingle:transports:ibb:1'
+NS_JINGLE_IBB = "urn:xmpp:jingle:transports:ibb:1"
 
 PLUGIN_INFO = {
     C.PI_NAME: "Jingle In-Band Bytestreams",
@@ -43,52 +44,58 @@
     C.PI_DEPENDENCIES: ["XEP-0166", "XEP-0047"],
     C.PI_MAIN: "XEP_0261",
     C.PI_HANDLER: "yes",
-    C.PI_DESCRIPTION: _("""Implementation of Jingle In-Band Bytestreams""")
+    C.PI_DESCRIPTION: _("""Implementation of Jingle In-Band Bytestreams"""),
 }
 
 
 class XEP_0261(object):
-    NAMESPACE = NS_JINGLE_IBB # used by XEP-0260 plugin for transport-replace
+    NAMESPACE = NS_JINGLE_IBB  # used by XEP-0260 plugin for transport-replace
 
     def __init__(self, host):
         log.info(_("plugin Jingle In-Band Bytestreams"))
         self.host = host
-        self._j = host.plugins["XEP-0166"] # shortcut to access jingle
-        self._ibb = host.plugins["XEP-0047"] # and in-band bytestream
-        self._j.registerTransport(NS_JINGLE_IBB, self._j.TRANSPORT_STREAMING, self, -10000) # must be the lowest priority
+        self._j = host.plugins["XEP-0166"]  # shortcut to access jingle
+        self._ibb = host.plugins["XEP-0047"]  # and in-band bytestream
+        self._j.registerTransport(
+            NS_JINGLE_IBB, self._j.TRANSPORT_STREAMING, self, -10000
+        )  # must be the lowest priority
 
     def getHandler(self, client):
         return XEP_0261_handler()
 
     def jingleSessionInit(self, client, session, content_name):
         transport_elt = domish.Element((NS_JINGLE_IBB, "transport"))
-        content_data = session['contents'][content_name]
-        transport_data = content_data['transport_data']
-        transport_data['block_size'] = self._ibb.BLOCK_SIZE
-        transport_elt['block-size'] = unicode(transport_data['block_size'])
-        transport_elt['sid'] = transport_data['sid'] = unicode(uuid.uuid4())
+        content_data = session["contents"][content_name]
+        transport_data = content_data["transport_data"]
+        transport_data["block_size"] = self._ibb.BLOCK_SIZE
+        transport_elt["block-size"] = unicode(transport_data["block_size"])
+        transport_elt["sid"] = transport_data["sid"] = unicode(uuid.uuid4())
         return transport_elt
 
     def jingleHandler(self, client, action, session, content_name, transport_elt):
-        content_data = session['contents'][content_name]
-        transport_data = content_data['transport_data']
-        if action in (self._j.A_SESSION_ACCEPT,
-                      self._j.A_ACCEPTED_ACK,
-                      self._j.A_TRANSPORT_ACCEPT):
+        content_data = session["contents"][content_name]
+        transport_data = content_data["transport_data"]
+        if action in (
+            self._j.A_SESSION_ACCEPT,
+            self._j.A_ACCEPTED_ACK,
+            self._j.A_TRANSPORT_ACCEPT,
+        ):
             pass
         elif action in (self._j.A_SESSION_INITIATE, self._j.A_TRANSPORT_REPLACE):
-            transport_data['sid'] = transport_elt['sid']
+            transport_data["sid"] = transport_elt["sid"]
         elif action in (self._j.A_START, self._j.A_PREPARE_RESPONDER):
-            peer_jid = session['peer_jid']
-            sid = transport_data['sid']
-            stream_object = content_data['stream_object']
+            peer_jid = session["peer_jid"]
+            sid = transport_data["sid"]
+            stream_object = content_data["stream_object"]
             if action == self._j.A_START:
-                block_size = transport_data['block_size']
-                d = self._ibb.startStream(client, stream_object, peer_jid, sid, block_size)
-                d.chainDeferred(content_data['finished_d'])
+                block_size = transport_data["block_size"]
+                d = self._ibb.startStream(
+                    client, stream_object, peer_jid, sid, block_size
+                )
+                d.chainDeferred(content_data["finished_d"])
             else:
                 d = self._ibb.createSession(client, stream_object, peer_jid, sid)
-                d.chainDeferred(content_data['finished_d'])
+                d.chainDeferred(content_data["finished_d"])
         else:
             log.warning(u"FIXME: unmanaged action {}".format(action))
         return transport_elt
@@ -97,8 +104,8 @@
 class XEP_0261_handler(XMPPHandler):
     implements(iwokkel.IDisco)
 
-    def getDiscoInfo(self, requestor, target, nodeIdentifier=''):
+    def getDiscoInfo(self, requestor, target, nodeIdentifier=""):
         return [disco.DiscoFeature(NS_JINGLE_IBB)]
 
-    def getDiscoItems(self, requestor, target, nodeIdentifier=''):
+    def getDiscoItems(self, requestor, target, nodeIdentifier=""):
         return []