@abstractmethod
  def should_fire(self, watermark, window, context):
    pass
call samtools to merge a list of bams hierarchically
dataset/ETHPy150Open GoogleCloudPlatform/DataflowPythonSDK/google/cloud/dataflow/transforms/trigger.py/TriggerFn.should_fire--crossover with--dataset/ETHPy150Open adamewing/bamsurgeon/bamsurgeon/common.py/mergebams