\section{Assumptions}\label{sec:assumptions}
The following assumptions are made for the implementation of the node placement algorithm:
\begin{itemize}
    \item There are no hyperedges.
    \item There are no port constraints.
    \item There are no labels.
    \item There are no cross-hierarchy edges.
\end{itemize}

\section{Input File Format}\label{sec:inputFileFormat}
The input to \appname is a JSON file.
An example is displayed in figure~\ref{fig:json-example}.
The structure is as follows:
\begin{itemize}
    \item The object in the JSON file is a node.
    \item A node has the attributes that are displayed in table~\ref{table:node-attributes}.
    \item An edge has the attributes that are displayed in table~\ref{table:edge-attributes}.
\end{itemize}
For parsing the JSON file the JSON-java library~\cite{leary_json-java:_2018} is used.


\centering
\begin{longtable}{|p{1.8cm}|p{2cm}|p{1.8cm}|p{8.5cm}|}
    \hline
    Attribute & Type & Optional & Explanation \\\hline\hline
    name & string & yes & If not omitted, this must be unique for a given parent node. \\\hline
    width & integer & yes & The minimum width of the node.
    The node can be wider if it contains other nodes that need more space. \\\hline
    height & integer & yes & The minimum height of the node.
    The node can be higher if it contains other nodes that need more space. \\\hline
    layers & list of lists of nodes & yes & The layers of nodes inside this node (Hierarchy). \\\hline
    edges & list of edges & yes & The edges between nodes whose parent node is this node. \\\hline
\caption{Node Attributes}
\label{table:node-attributes}
\end{longtable}

\begin{longtable}{|p{1.8cm}|p{2cm}|p{1.8cm}|p{8.5cm}|}
    \hline
    Attribute & Type & Optional & Explanation \\\hline\hline
    source & string & no & The name of the source of this edge.
    Must be a node with the same parent node as the node specified by the \enquote{target} attribute. \\\hline
    target & string & no & The name of the target of this edge.
    Must be a node with the same parent node as the node specified by the \enquote{source} attribute. \\\hline
\caption{Edge Attributes}
\label{table:edge-attributes}
\end{longtable}
\raggedright

%\begin{figure}[tp]
%    \centering
%    \includegraphics[width=0.9\textwidth]{img/json.png}
%    \caption[Input file format]{Input file format illustrated as a HERM diagram}
%    \label{fig:iff}
%\end{figure}

\begin{figure}
    \begin{lstlisting}[language=json,emph={}]
    {
       "layers":[
          [
             {
                "name":"n2",
                "width":10,
                "height":10
             },
             {
                "name":"n1",
                "width":10,
                "height":10,
                "layers":[
                   [
                      {
                         "name":"n2",
                         "width":10,
                         "height":10
                      }
                   ]
                ]
             }
          ]
       ],
       "name":"n0"
    }
    \end{lstlisting}
    \caption[Example Input File]{Example Input file that is understood by \appname.}
    \label{fig:json-example}
\end{figure}

\section{Class Diagrams}\label{sec:classDiagrams}
\TODO{run vpp}