def save(self, doc):
        if doc.id:
            return self.update(doc)
        else:
            return self.insert(doc)
def connection_made(self, transport):
        self.transport = transport
        # Here the buffer is intended to be copied, so that the outgoing buffer
        # won't be wrongly updated by next read
        self.buffer = bytearray(256 * 1024)