There's a bug currently that warpgrapher allows the creation of multiple relationships for non-list properties. The intent is to fix that bug by precluding the creation of a second relationship when one already exists, returning an error. It will be possible to replace a single-node (non-list) relationship by first deleting the old relationship, then creating a new one. However, it may be more convenient, in some cases, to do so in a single client request, which would be possible with a REPLACE operation.
There's a bug currently that warpgrapher allows the creation of multiple relationships for non-list properties. The intent is to fix that bug by precluding the creation of a second relationship when one already exists, returning an error. It will be possible to replace a single-node (non-list) relationship by first deleting the old relationship, then creating a new one. However, it may be more convenient, in some cases, to do so in a single client request, which would be possible with a REPLACE operation.