(null)
+- test:x:1
+- test:a:1
|  \- test:b:1
|     \- test:x:3
+- test:c:1
|  \- test:x:2
\- test:d:1
   \- test:e:1
      \- test:x:2[2,)   # forces rejection of x:1, should fallback to nearest and not first-seen, i.e. x:2 and not x:3
