`TCustomLayer`
pt		Invalid
pt		ForceUpdate
		Cursor
		Index
		LayerCollection
		LayerOptions
	ro	LayerStates
		MouseEvents
		Tag
		Visible

`TNotifiablePersistent`
pt	ro	UpdateCount
pt	ro	LockUpdateCount
pt	ro	Modified

`TPlainInterfacedPersistent`
pt		RefCounted
	ro	RefCount