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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_hlu(self, resource, cg_member=None):
 """Gets the hlu number of a lun, lun snap, cg snap or a member snap of cg snap. :param resource: can be lun, lun snap, cg snap or a member snap of cg snap. :param cg_member: the member lun of cg if `lun_or_snap` is cg snap. :return: the hlu number. """

        host_lun = self.get_host_lun(resource, cg_member=cg_member)
        return host_lun if host_lun is None else host_lun.hlu