[Libguestfs] sample code for guestfs_hivex_node_set_value

Is there any sample code available to demonstrate the use of the guestfs_hivex_node_set_value API? I have no problem traversing and reading keys using libguestfs hivex wrappers - but continue to fail on any write attempts. The return is always -1 and errno is unchanged. I've set the environment variable HIVEX_DEBUG to 1 on a chance that this may help - but it doesn't. The only sample I can find in the sources that use hivex is the "virt-dhcp-address.c" sample. But it does not write to the registry.