#18600: In 3.3, as_string does not accept a policy keyword.

Also, document the policy keyword that was added to Message in 3.3.

Doc/library/email.message.rst

@@ -31,9 +31,15 @@ parameters, and for recursively walking over the object tree.
 Here are the methods of the :class:`Message` class:
 
 
-.. class:: Message()
+.. class:: Message(policy=compat32)
 
-   The constructor takes no arguments.
+   The *policy* argument determiens the :mod:`~email.policy` that will be used
+   to update the message model.  The default value, :class:`compat32
+   <email.policy.Compat32>` maintains backward compatibility with the
+   Python 3.2 version of the email package.  For more information see the
+   :mod:`~email.policy` documentation.
+
+   .. versionchanged:: 3.3 The *policy* keyword argument was added.
 
 
    .. method:: as_string(unixfrom=False, maxheaderlen=0)

Doc/library/email.policy.rst

@@ -97,16 +97,6 @@ correct line separator characters when creating the binary string to feed into
 ``sendmail's`` ``stdin``, where the default policy would use ``\n`` line
 separators.
 
-Some email package methods accept a *policy* keyword argument, allowing the
-policy to be overridden for that method.  For example, the following code uses
-the :meth:`~email.message.Message.as_string` method of the *msg* object from
-the previous example and writes the message to a file using the native line
-separators for the platform on which it is running::
-
-   >>> import os
-   >>> with open('converted.txt', 'wb') as f:
-   ...     f.write(msg.as_string(policy=msg.policy.clone(linesep=os.linesep)))
-
 Policy objects can also be combined using the addition operator, producing a
 policy object whose settings are a combination of the non-default values of the
 summed objects::