\defverbatim[colored]\testcode{
		\begin{lstlisting}
\documentclass{article}

\begin{document}
	Hello world!
\end{document}
		\end{lstlisting}
	}
	\begin{frame}
	\only<1>{
		\frametitle{Hello World!}
		\testcode
	}
	\only<2>{
		\frametitle{Header}
		\testcode
	}
	\end{frame}