feature - ip link set <dev> primary <dev> ?

Should there be an

 ip link set <primary-slave-device> primary <master-device>

command in the iproute2 package, to set the Primary Slave on a "bond" type link?

It seems that the alternative now is to use the sysfs, with

 echo -n <primary> > /sys/devices/virtual/net/<master-device>/bonding/primary

which, in systemd Service Unit Files, requires "/usr/bin/sh -c 'echo ...'"
rather than simply "/usr/bin/echo ...".  "ip" seems to handle all other "bond"
configuration itself.

Thanks
James