Undoes the last edit operation in the text control.
NuGet Package: DevExpress.Wpf.Core
If the editor is masked, it stores only one previous value of its content. In this instance, calling the Undo method several times in succession results in switching the editor’s content between the current and the previous values. If the editor is unmasked, multiple previous values can be restored.
An end-user can undo the last edit operation by pressing the CTRL+Z key combination.