#27331: add policy keyword argument to all MIME subclasses.

Patch by Berker Peksag.
diff --git a/Lib/email/mime/message.py b/Lib/email/mime/message.py
index 275dbfd..07e4f2d 100644
--- a/Lib/email/mime/message.py
+++ b/Lib/email/mime/message.py
@@ -14,7 +14,7 @@
 class MIMEMessage(MIMENonMultipart):
     """Class representing message/* MIME documents."""
 
-    def __init__(self, _msg, _subtype='rfc822'):
+    def __init__(self, _msg, _subtype='rfc822', *, policy=None):
         """Create a message/* type MIME document.
 
         _msg is a message object and must be an instance of Message, or a
@@ -24,7 +24,7 @@
         default is "rfc822" (this is defined by the MIME standard, even though
         the term "rfc822" is technically outdated by RFC 2822).
         """
-        MIMENonMultipart.__init__(self, 'message', _subtype)
+        MIMENonMultipart.__init__(self, 'message', _subtype, policy=policy)
         if not isinstance(_msg, message.Message):
             raise TypeError('Argument is not an instance of Message')
         # It's convenient to use this base class method.  We need to do it