Last round of adapting style of documenting argument default values.
diff --git a/Doc/library/xml.dom.rst b/Doc/library/xml.dom.rst
index bf1b151..fe21804 100644
--- a/Doc/library/xml.dom.rst
+++ b/Doc/library/xml.dom.rst
@@ -1,4 +1,3 @@
-
:mod:`xml.dom` --- The Document Object Model API
================================================
@@ -96,7 +95,7 @@
implementation supports some customization).
-.. function:: getDOMImplementation([name[, features]])
+.. function:: getDOMImplementation(name=None, features=())
Return a suitable DOM implementation. The *name* is either well-known, the
module name of a DOM implementation, or ``None``. If it is not ``None``, imports