def GetPrev ( self ):
        editor = self.editor
        if (editor is not None) and (editor.previous != ''):
            previous = editor.previous
            if previous is None:
                return None
            for page in self.pages:
                if page.id == previous:
                    return page
        return self.previous

#-------------------------------------------------------------------------------
#  'PageGroupEditor' class:
#-------------------------------------------------------------------------------
Returns the previous page to this one.
dataset/ETHPy150Open enthought/traitsui/traitsui/wx/ui_wizard.py/UIWizardPage.GetPrev