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 setup_dependent_build_environment(self, env, dependent_spec):
        """Location of the OpenFOAM project directory.
        This is identical to the WM_PROJECT_DIR value, but we avoid that
        variable since it would mask the normal OpenFOAM cleanup of
        previous versions.
        """
        env.set('FOAM_PROJECT_DIR', self.projectdir)