@staticmethod
def is_valid(control_instance, *args, **kwargs):
    """ Method to check if the new control values are correct.

        If the new list controls values are not correct, the backroung
        color of each control in the list will be red.

        Parameters
        ----------
        control_instance: QFrame (mandatory)
            the control widget we want to validate

        Returns
        -------
        valid: bool
            True if the control values are valid,
            False otherwise
        """
    valid = True
    return valid
