code: def setLineEdit(self, edit):
          
          if edit and not isinstance(edit, XLineEdit):
              edit.setParent(None)
              edit.deleteLater()
              
              edit = XLineEdit(self)
          
          if edit is not None:
              edit.installEventFilter(self)
              self._lineEdit = weakref.ref(edit)
          else:
              self._lineEdit = None
          
          super(XComboBox, self).setLineEdit(edit)
docs: Sets the line edit for this widget.
          
          :warning    If the inputed edit is NOT an instance of XLineEdit, \
                      this method will destroy the edit and create a new \
                      XLineEdit instance.
          
          :param      edit | <XLineEdit>