AddSubCmd

Adds an action to a composite command.

Adopt

Merges adjacent commands in the history queue if they are related.

Execute

Carries out an action, usually changing the diagram in some way.

IsContainerOf

Determines whether a command has been initiated by this command and should be treated as a derivative.

Redo

Repeats an action that has been undone.

Undo

Undoes an action, restoring the diagram to the state it was in before carrying out the action.