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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 derive_identity_arf(name, arf):
 """Create an "identity" ARF that has uniform sensitivity. *name* The name of the ARF object to be created; passed to Sherpa. *arf* An existing ARF object on which to base this one. Returns: A new ARF1D object that has a uniform spectral response vector. In many X-ray observations, the relevant background signal does not behave like an astrophysical source that is filtered through the telescope's response functions. However, I have been unable to get current Sherpa (version 4.9) to behave how I want when working with backround models that are *not* filtered through these response functions. This function constructs an "identity" ARF response function that has uniform sensitivity as a function of detector channel. """

    from sherpa.astro.data import DataARF
    from sherpa.astro.instrument import ARF1D

    darf = DataARF(
        name,
        arf.energ_lo,
        arf.energ_hi,
        np.ones(arf.specresp.shape),
        arf.bin_lo,
        arf.bin_hi,
        arf.exposure,
        header = None,
    )
    return ARF1D(darf, pha=arf._pha)