def write(self, record):
    if not self._writer:
      raise HdfsError('Avro writer not available outside context block.')
    self._writer.send(record)
The only way a write pipe can become "readable" is at EOF, because the
dataset/ETHPy150Open mtth/hdfs/hdfs/ext/avro/__init__.py/AvroWriter.write--crossover with--dataset/ETHPy150Open twisted/twisted/twisted/internet/process.py/ProcessWriter.doRead