```mermaid
  graph TD;
      A-->B;
      A-->C;
      B-->D;
      C-->D;
```

```mermaid
    stateDiagram
    [*] --> Active

    state Active {
        [*] --> NumLockOff
        NumLockOff --> NumLockOn : EvNumLockPressed
        NumLockOn --> NumLockOff : EvNumLockPressed
    }
```