def __init__(self, *futures):
    """Initializer.

    Args:
      *futures: PipelineFutures that all subsequent pipelines should follow.
        May be empty, in which case this statement does nothing.
    """
    for f in futures:
      if not isinstance(f, PipelineFuture):
        raise TypeError('May only pass PipelineFuture instances to After(). %r',
                        type(f))
    self._futures = set(futures)
def __init__ ( self , * futures ) : for f in futures : if not isinstance ( f , PipelineFuture ) : raise TypeError ( 'May only pass PipelineFuture instances to After(). %r' , type ( f ) ) self . _futures = set ( futures )
Initializer.

    Args:
      *futures: PipelineFutures that all subsequent pipelines should follow.
        May be empty, in which case this statement does nothing.