\begin{sequencediagram}
    \newthread{actor}{Actor}{}
    \newinst[3]{concordia}{:Concordia}{}
    \newinst[2]{eth}{:Ethereum}{}
    \newinst[1]{orbit}{:OrbitDB}{}

    \begin{call}{actor}{Create post}{concordia}{Post creation form}
    \end{call}

    \begin{call}{actor}{Submit}{concordia}{Updated topic page}

        \begin{call}{concordia}{Create post}{eth}{New post ID}
        \end{call}

        \begin{call}{concordia}{Save post information}{orbit}{}
        \end{call}

    \end{call}
\end{sequencediagram}
