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

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

 \begin{class}[text width=7cm]{CheckingAccount}{-5,-5}
   \inherit{BankAccount}
   \attribute{insufficientFundsFee : Dollars}

   \operation{processCheck ( checkToProcess : Check )}
   \operation{withdrawal ( amount : Dollars )}
 \end{class}

 \begin{class}[text width=7cm]{SavingsAccount}{5,-5}
   \inherit{BankAccount}
   \attribute{annualInteresRate : Percentage}

   \operation{depositMonthlyInterest ( )}
   \operation{withdrawal ( amount : Dollars )}
 \end{class}

\end{tikzpicture}