Add method to ABC and update VoiceRegion enum

discord/abc.py

@@ -190,6 +190,9 @@ class PrivateChannel(Snowflake, Protocol):
 
     me: ClientUser
 
+    def _add_call(self, **kwargs):
+        raise NotImplementedError
+
 
 class _Overwrites:
     __slots__ = ('id', 'allow', 'deny', 'type')

discord/enums.py

@@ -254,9 +254,12 @@ class VoiceRegion(Enum):
     frankfurt = 'frankfurt'
     brazil = 'brazil'
     hongkong = 'hongkong'
+    hong_kong = 'hongkong'
+    rotterdam = 'rotterdam'
     russia = 'russia'
     japan = 'japan'
     southafrica = 'southafrica'
+    south_africa = 'southafrica'
     south_korea = 'south-korea'
     india = 'india'
     europe = 'europe'