code/datums/extensions/lockable.dm 
| /decl/observ/lock_state_changed | Sent by the lockable when it's been locked or unlocked. |
|---|---|
| /decl/observ/lock_panel_state_changed | Sent by lockable when the service panel is opened/closed. |
| /datum/extension/lockable | Extension for giving an object a code lock, with it's own ui. |