Association

\begin{figure}
  \centering
  \begin{tikzpicture}
    \umlclass{CurrentAccount}{
      accountNumber: Integer \\
      balance: Real \\
      overdraftLimit: Real \\
      holderForename: String \\
      holderSurname: String \\
      holderAddress: String
    }{
      getBalance(): Real \\
      deposit(amount: Real) \\
      withdraw(amount: Real): Boolean
    };
  \end{tikzpicture}
  \label{fig:assoc-eg-1}
  \caption{An example of a badly modelled class with attributes not dependent on the class itself.}
\end{figure}

\begin{figure}
  \label{fig:assoc-eg-2}
  \centering
  \begin{tikzpicture}
    \umlclass{CurrentAccount}{
      accountNumber: Integer \\
      balance: Real \\
      overdraftLimit: Real \\
    }{
      getBalance(): Real \\
      deposit(amount: Real) \\
      withdraw(amount: Real): Boolean
    };

    \umlclass[x=9]{Holder}{
      forename: String \\
      surname: String
    }{
      getForename(): String \\
      getSurname(): String \\
      getAddress(): String
    };
    \umlsimpleclass[x=9, y=-4]{Address};

    \umlassoc[attr1=account|1..*, attr2=holder|1..*]{CurrentAccount}{Holder};
    \umlassoc[attr1=householder|1..*, attr2=domicile|1]{Holder}{Address};
  \end{tikzpicture}
  \caption{Improved version of \autoref{fig:assoc-eg-1} with propper associations and multiplicities.}
\end{figure}