Checks for valid given value and appropriate units with uncertainty.

        Args:
            isvalid_uncertainty (`bool`): flag from schema indicating uncertainty to be checked
            field (`str`): property associated with the quantity in question.
            value (`list`): list with the string of the value of the quantity and a dictionary of
                the uncertainty

        The rule's arguments are validated against this schema:
            {'isvalid_uncertainty': {'type': 'bool'}, 'field': {'type': 'str'},
             'value': {'type': 'list'}}

def _validate_isvalid_uncertainty(self, isvalid_uncertainty, field, value):
        """Checks for valid given value and appropriate units with uncertainty.

        Args:
            isvalid_uncertainty (`bool`): flag from schema indicating uncertainty to be checked
            field (`str`): property associated with the quantity in question.
            value (`list`): list with the string of the value of the quantity and a dictionary of
                the uncertainty

        The rule's arguments are validated against this schema:
            {'isvalid_uncertainty': {'type': 'bool'}, 'field': {'type': 'str'},
             'value': {'type': 'list'}}
        """
        self._validate_isvalid_quantity(True, field, value)

        # This len check is necessary for reasons that aren't quite clear to me
        # Cerberus calls this validation method even when lists have only one element
        # and should therefore be validated only by isvalid_quantity
        if len(value) > 1 and value[1]['uncertainty-type'] != 'relative':
            if value[1].get('uncertainty') is not None:
                self._validate_isvalid_quantity(True, field, [value[1]['uncertainty']])

            if value[1].get('upper-uncertainty') is not None:
                self._validate_isvalid_quantity(True, field, [value[1]['upper-uncertainty']])

            if value[1].get('lower-uncertainty') is not None:
                self._validate_isvalid_quantity(True, field, [value[1]['lower-uncertainty']])