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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 _check_quantiles(self, val):
 """ Validate the quantiles passed in. Returns the np array if valid. """

        if len(val) != 3 or not is_monotonic(val) or not np.all(val < 1):
            raise YellowbrickValueError(
                "quantiles must be a sequence of three "
                "monotonically increasing values less than 1"
            )
        return np.asarray(val)