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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 get_measurement_sampler(n_sample, run_options=None):
 """Returns a function which get the expectations by sampling the measured circuit"""

    if run_options is None:
        run_options = {}

    def sampling_by_measurement(circuit, meas):
        def reduce_bits(bits, meas):
            bits = [int(x) for x in bits[::-1]]
            return tuple(bits[m] for m in meas)

        meas = tuple(meas)
        circuit.measure[meas]
        counter = circuit.run(shots=n_sample, returns="shots", **run_options)
        counts = Counter({reduce_bits(bits, meas): val for bits, val in counter.items()})
        return {k: v / n_sample for k, v in counts.items()}

    return sampling_by_measurement