%\begin{tikzpicture}[scale=0.7,transform shape]
\begin{tikzpicture}[scale=1,transform shape]

  \begin{class}{Graph}{0,0}
  \end{class}
  
  \begin{class}{Arc}{3,-3}
    \attribute{weight : Int}
  \end{class}
  
  \begin{class}{Node}{-3,-3}
    \attribute{name : String}
  \end{class}
  
  \composition{Graph}{nodes}{*}{Node}
  \unidirectionalAssociation{Node}{graph}{1}{Graph}
  
  \composition{Graph}{arcs}{*}{Arc}
  \unidirectionalAssociation{Arc}{graph}{1}{Graph}

  %\association{Arc}{source}{1}{Node}{0..*}{outgoings}
  \myassociation{Node}{source}{1}{Arc}{*}{outgoings}{0,-3.0}{0}

  %\association{Arc}{target}{1}{Node}{0..*}{incomings}
  \myassociation{Node}{target}{1}{Arc}{*}{incomings}{0,-4.5}{1}

\end{tikzpicture}