classDiagram
  class BankAccount {
    +String owner
    -int balance
    +deposit(int amount) void
    +withdraw(int amount) bool
    -validate() bool
  }
---
┌─────────────────┐    
│ BankAccount     │    
├─────────────────┤    
│ +owner: String  │    
│ -balance: int   │    
├─────────────────┤    
│ +deposit: void  │    
│ +withdraw: bool │    
│ -validate: bool │    
└─────────────────┘