def add(self, elem, replace=False):
        """Add a requirement.

        :param elem: a string or :class:`Requirement` instance.
        :param replace: if `True`, packages in the set with the same name will
            be removed first.
        """
        if isinstance(elem, text_type):
            elem = Requirement.coerce(elem)
        if replace and elem in self:
            self.remove(elem)
        super(Requirements, self).add(elem)
def config(self):
        settings = {
            # Use SYSTEMMPI since openfoam-org doesn't have USERMPI
            'mplib': 'SYSTEMMPI',

            # Add links into bin/, lib/ (eg, for other applications)
            'link': False,
        }
        # OpenFOAM v2.4 and earlier lacks WM_LABEL_OPTION
        if self.spec.satisfies('@:2.4'):
            settings['label-size'] = False
        return settings