Manual/Function/ISFUNC

If you include the following in any menu, you can add an item only when there is a corresponding function. This is useful when you do not want to include debug menus in the distributed files.
```
//Debug menu
if ( ISFUNC("DebugMenu") )
{
	AYATEMPLATE.MenuItem( "【Debug menu】","DebugMenu")
}
```

In combination with the "On_enable_debug" event, the following can be used to add an item only when "SHIORI debug mode" is enabled in the dev palette.

//Debug menu
if ( ISFUNC("DebugMenu") && debug_mode )
{
	AYATEMPLATE.MenuItem( "【Debug menu】","DebugMenu")
}

//Note the check status of "SHIORI debug mode enabled"
On_enable_debug
{
	debug_mode = reference[0]
}