code: def flushdb(self, async_op=False):
          
          if async_op:
              fut = self.execute(b'FLUSHDB', b'ASYNC')
          else:
              fut = self.execute(b'FLUSHDB')
          return wait_ok(fut)
docs: Remove all keys from the current database.
  
          :param async_op: lets a single database to be freed asynchronously. \
          Defaults to False