get the action that can undo the last user interaction on this project . concode_field_sep ProjectActions theInstance concode_elem_sep ActionRemoveFromDiagram removeFromDiagram concode_elem_sep AbstractAction redoAction concode_elem_sep ActionUndo undoAction concode_field_sep void determineRemoveEnabled concode_elem_sep void targetSet concode_elem_sep void jumpToDiagramShowing concode_elem_sep AbstractAction getRedoAction concode_elem_sep void targetRemoved concode_elem_sep AbstractAction getRemoveFromDiagramAction concode_elem_sep void setTarget concode_elem_sep void propertyChange concode_elem_sep ProjectActions getInstance concode_elem_sep void targetAdded