When a pickled class instance is unpickled, its \method{__init__()}
method is normally \emph{not} invoked. If it is desirable that the
-\method{__init__()} method be called on unpickling, a class can define
-a method \method{__getinitargs__()}, which should return a
+\method{__init__()} method be called on unpickling, an old-style class
+can define a method \method{__getinitargs__()}, which should return a
\emph{tuple} containing the arguments to be passed to the class
constructor (i.e. \method{__init__()}). The
\method{__getinitargs__()} method is called at
\withsubitem{(copy protocol)}{\ttindex{__getinitargs__()}}
\withsubitem{(instance constructor)}{\ttindex{__init__()}}
+New-style types can provide a \method{__getnewargs__()} method that is
+used for protocol 2. Implementing this method is needed if the type
+establishes some internal invariants when the instance is created, or
+if the memory allocation is affected by the values passed to the
+\method{__new__()} method for the type (as it is for tuples and
+strings). Instances of a new-style type \class{C} are created using
+
+\begin{alltt}
+obj = C.__new__(C, *\var{args})
+\end{alltt}
+
+where \var{args} is the result of calling \method{__getnewargs__()} on
+the original object; if there is no \method{__getnewargs__()}, an
+empty tuple is assumed.
+
\withsubitem{(copy protocol)}{
\ttindex{__getstate__()}\ttindex{__setstate__()}}
\withsubitem{(instance attribute)}{