@startuml
class CommandHandler {
    + {static} getInstance() : CommandHandler
    + createBlock(prefabId:string, position:Vector3, rotation:Quaternion) : void
    + moveBlock(blockId:string, prePosition:Vector3, newPosition:Vector3, preRotation:Quaternion, newRotation:Quaternion) : void
    + removeBlock(blockId:string) : void
    + removeGroup(blockIds:List<string>) : void
    + rotateBlock(blockId:string, newRotation:Quaternion) : void
    + undoAction() : void
    + redoAction() : void
    + clearHistory() : void
}
MonoBehaviour <|-- CommandHandler
@enduml