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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def intervalsubtract(left, right, lstart='start', lstop='stop', rstart='start', rstop='stop', lkey=None, rkey=None, include_stop=False):
 """ Subtract intervals in the right hand table from intervals in the left hand table. """


    assert (lkey is None) == (rkey is None), \
        'facet key field must be provided for both or neither table'
    return IntervalSubtractView(left, right, lstart=lstart, lstop=lstop,
                                rstart=rstart, rstop=rstop, lkey=lkey,
                                rkey=rkey, include_stop=include_stop)