fix: xen domains memory was wrong

            cls._instance = super(XenHypervisor, cls).__new__(cls, *args,

                                                                    **kwargs)

        return cls._instance

    def get_mem(self):

        '''

        '''

        # real machine memory is the max allocatable size of the Dom0

        mem = None

        try:

            dom0 = self._lvcon_handle.lookupByID(0)

            data = dom0.info()[1]

            if data:

                mem = data

        except:

            pass

        return mem

    def get_mem_free(self):

        '''

        '''

        return None

    def get_mem_used(self):

        '''

        '''

        return None