\begin{tikzpicture}
 \begin{package}{Accounts}
   \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{package}

\end{tikzpicture}