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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 add_ch_grp_to_interface( self, nexus_host, if_type, port, ch_grp):
 """Applies channel-group n to ethernet interface."""


        if if_type != "ethernet":
            LOG.error("Unexpected interface type %(iftype)s when "
                      "adding change group", {'iftype': if_type})
            return

        starttime = time.time()

        path_snip = snipp.PATH_ALL
        path_interface = "phys-[eth" + port + "]"

        body_snip = snipp.BODY_ADD_CH_GRP % (ch_grp, ch_grp, path_interface)

        self.send_edit_string(nexus_host, path_snip, body_snip)

        self.capture_and_print_timeshot(
            starttime, "add_ch_group",
            switch=nexus_host)