Use new optional argument style in email docs.
diff --git a/Doc/library/email.iterators.rst b/Doc/library/email.iterators.rst
index f7ca9e4..6c35b79 100644
--- a/Doc/library/email.iterators.rst
+++ b/Doc/library/email.iterators.rst
@@ -10,7 +10,7 @@
useful higher level iterations over message object trees.
-.. function:: body_line_iterator(msg[, decode])
+.. function:: body_line_iterator(msg, decode=False)
This iterates over all the payloads in all the subparts of *msg*, returning the
string payloads line-by-line. It skips over all the subpart headers, and it
@@ -21,7 +21,7 @@
Optional *decode* is passed through to :meth:`Message.get_payload`.
-.. function:: typed_subpart_iterator(msg[, maintype[, subtype]])
+.. function:: typed_subpart_iterator(msg, maintype='text', subtype=None)
This iterates over all the subparts of *msg*, returning only those subparts that
match the MIME type specified by *maintype* and *subtype*.
@@ -37,7 +37,7 @@
*not* be considered part of the supported public interface for the package.
-.. function:: _structure(msg[, fp[, level]])
+.. function:: _structure(msg, fp=None, level=0, include_default=False)
Prints an indented representation of the content types of the message object
structure. For example::
@@ -62,4 +62,4 @@
Optional *fp* is a file-like object to print the output to. It must be
suitable for Python's :func:`print` function. *level* is used internally.
-
+ *include_default*, if true, prints the default type as well.