POSTing an openconfig neghbor fails

I was following the user guide, https://wiki.opendaylight.org/view/BGP_LS_PCEP:Beryllium_User_Guide#BGP_Peer_3, to add a peer neighbor but it failed with:

java.lang.IllegalArgumentException: Node (http://openconfig.net/yang/bgp?revision=2015-10-09)bgp is missing mandatory descendant /(http://openconfig.net/yang/bgp?revision=2015-10-09)global/config/as

The global container is a sibling of neighbors but it has a mandatory child descendant. The only way I could get it to work as is was to PUT the entire bgp tree in order to include global and the mandatory leaf:

<bgp xmlns="http://openconfig.net/yang/bgp">
<global>
<config>
<as>64496</as>
</config>
</global>
...
<neighbors>
<neighbor>
<neighbor-address>192.0.2.1</neighbor-address>
...
</neighbor>
</neighbors>
</bgp>

This is not very usable. After adding "presence" to the global container, it works as expected as per the guide.