a method to remove docs from the collection
            
        :param doc_ids: string or list of strings with document ids to purge 
        :return: list of strings of doc ids purged

def purge(self, doc_ids):

        '''
            a method to remove docs from the collection
            
        :param doc_ids: string or list of strings with document ids to purge 
        :return: list of strings of doc ids purged
        '''
        
        # https://developer.couchbase.com/documentation/mobile/1.5/references/sync-gateway/admin-rest-api/index.html#/document/post__db___purge
    
        title = '%s.purge' % self.__class__.__name__
        
    # ingest arguments
        if isinstance(doc_ids, str):
            doc_ids = [ doc_ids ]
        
    # validate inputs
        input_fields = {
            'doc_ids': doc_ids
        }
        for key, value in input_fields.items():
            object_title = '%s(%s=%s)' % (title, key, str(value))
            self.fields.validate(value, '.%s' % key, object_title)
    
    # construct request fields
        url = self.bucket_url + '/_purge'
        json_body = {}
        for doc in doc_ids:
            json_body[doc] = [ "*" ]
    
    # send request 
        response = requests.post(url, json=json_body)

    # construct output from response
        purged_list = []
        purged_map = {}
        response_details = response.json()
        if 'purged' in response_details.keys():
            purged_map = response_details['purged']
        for key in purged_map.keys():
            purged_list.append(key)
        
        return purged_list