def _validate_incompatibilities(self, incompatibles):
        """Used by the bowtie _validate method (PRIVATE)."""
        for element in incompatibles:
            if type(element) is list:
                i = [a for a in element if self._get_parameter(a)]
                if len(i) > 1:
                    raise ValueError("Options {} are incompatible".format(" and ".join(i)))
            elif type(incompatibles) is dict:
                if self._get_parameter(element):
                    for b in incompatibles[element]:
                        if self._get_parameter(b):
                            raise ValueError("Options %s and %s are incompatible."
                                             % (element, b))
            else:
                for a in element:
                    if self._get_parameter(a):
                        for b in incompatibles[a]:
                            if self._get_parameter(b):
                                raise ValueError("Options %s and %s are incompatible."
                                                 % (a, b))