Initialize CFBlanket from a CFG instance.

        :param cfg: A CFG instance.
        :return:    None

def _from_cfg(self, cfg):
        """
        Initialize CFBlanket from a CFG instance.

        :param cfg: A CFG instance.
        :return:    None
        """

        # Let's first add all functions first
        for func in cfg.kb.functions.values():
            self.add_function(func)

        self._mark_unknowns()