Documented the new AST constructor.
diff --git a/Doc/library/ast.rst b/Doc/library/ast.rst
index 3c2f8d2..4ce21c8 100644
--- a/Doc/library/ast.rst
+++ b/Doc/library/ast.rst
@@ -96,6 +96,11 @@
node = ast.UnaryOp(ast.USub(), ast.Num(5, lineno=0, col_offset=0),
lineno=0, col_offset=0)
+ .. versionadded:: 2.6
+ The constructor as explained above was added. In Python 2.5 nodes had
+ to be created by calling the class constructor without arguments and
+ setting the attributes afterwards.
+
.. _abstract-grammar: