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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 _unbind(cls, boundname):
 """ Unbinds a bound form to a WFN. :param string boundname: CPE name :returns: WFN object associated with boundname. :rtype: CPE2_3_WFN """


        try:
            fs = CPE2_3_FS(boundname)
        except:
            # CPE name is not formatted string
            try:
                uri = CPE2_3_URI(boundname)
            except:
                # CPE name is not URI but WFN
                return CPE2_3_WFN(boundname)
            else:
                return CPE2_3_WFN(uri.as_wfn())
        else:
            return CPE2_3_WFN(fs.as_wfn())