\begin{tikzpicture}

\begin{tikzpicture}
\begin{abstractclass}[text width=5cm]{BankAccount}{0,0}
\attribute{owner : String}
\attribute{balance : Dollars = 0}

\operation{deposit(amount : Dollars)}
\operation[0]{withdrawl(amount : Dollars)}
\end{abstractclass}
\end{tikzpicture}