Nested call in self call

[anneborcherding]

Hi there,

is there a way to correctly create a nested call in a self call? If I do it in the naive way, the arrows are not drawn correctly (they start from the original rectangle and not from the sub rountine rectangle, see below.)

\begin{sequencediagram}
    \newthread{A}{A}
    \newinst[1]{B}{B}

    \begin{call}{A}{call()}{A}{Ok}
       \begin{call}{A}{call()}{B}{Ok}
       \end{call}
    \end{call}

\end{sequencediagram}