'Creates a Quantizer pipeline.
Exactly one of `steps_per_quarter` and `steps_per_second` should be defined.
Args:
steps_per_quarter: Steps per quarter note to use for quantization.
steps_per_second: Steps per second to use for quantization.
name: Pipeline name.
Raises:
ValueError: If both or neither of `steps_per_quarter` and
`steps_per_second` are set.'

def __init__(self, steps_per_quarter=None, steps_per_second=None, name=None):

    super(Quantizer, self).__init__(name=name)
    if ((steps_per_quarter is not None) == (steps_per_second is not None)):
        raise ValueError('Exactly    one    of    steps_per_quarter    or    steps_per_second    must    be    set.')
    self._steps_per_quarter = steps_per_quarter
    self._steps_per_second = steps_per_second
