isValid
Check if this Engine is still valid (not destroyed).
Return
true if the Engine is valid and can be used, false if destroyed.
Check if this Engine is still valid (not destroyed).
Return
true if the Engine is valid and can be used, false if destroyed.
Check if this Engine is still valid (not destroyed).
Return
true if the Engine is valid and can be used, false if destroyed.
Check if this Engine is still valid (not destroyed).
Return
true if the Engine is valid and can be used, false if destroyed.