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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 undistortWCS(refwcs):
 """ Generate an undistorted HSTWCS from an HSTWCS object with a distortion model """

    wcslin = stwcs.distortion.utils.output_wcs([refwcs])

    outwcs = stwcs.wcsutil.HSTWCS()
    outwcs.wcs = wcslin.wcs
    outwcs.wcs.set()
    outwcs.setPscale()
    outwcs.setOrient()
    outwcs.sip = None

    # Update instrument specific keywords
    outwcs.inst_kw = refwcs.inst_kw
    for kw in refwcs.inst_kw:
        outwcs.__dict__[kw] = refwcs.__dict__[kw]
    outwcs.pixel_shape = wcslin.pixel_shape

    return outwcs