Return the results from master_tops if configured

def _master_tops(self, load, skip_verify=False):
        '''
        Return the results from master_tops if configured
        '''
        if not skip_verify:
            if 'id' not in load:
                log.error('Received call for external nodes without an id')
                return {}
            if not salt.utils.verify.valid_id(self.opts, load['id']):
                return {}
        # Evaluate all configured master_tops interfaces

        opts = {}
        grains = {}
        ret = {}

        if 'opts' in load:
            opts = load['opts']
            if 'grains' in load['opts']:
                grains = load['opts']['grains']
        for fun in self.tops:
            if fun not in self.opts.get('master_tops', {}):
                continue
            try:
                ret = salt.utils.dictupdate.merge(ret, self.tops[fun](opts=opts, grains=grains), merge_lists=True)
            except Exception as exc:
                # If anything happens in the top generation, log it and move on
                log.error(
                    'Top function %s failed with error %s for minion %s',
                    fun, exc, load['id']
                )
        return ret