\begin{tikzpicture}
\begin{umlstate}[name=Amain]{Global state of object A}
\begin{umlstate}[name=Bgraph, fill=red!20]{graphe B}
\umlbasicstate[y=-4, name=test1, fill=white]{test1}
\umlbasicstate[y=-8, name=test2, fill=white]{test2}
\end{umlstate}
\umlbasicstate[x=6, y=-6, name=visu, fill=green!20]{Visualisation}
\end{umlstate}
\end{tikzpicture}