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>

def setLineEdit(self, edit):
        """
        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>
        """
        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)