this should be >= 0 - particularly because the default is 0! It's non-negative.
A non-negative number that shall represents the length of leader line extensions that extend from the line proper 180 degrees from the leader lines, as shown in "Figure 80 — Leader lines".
Default value: 0 (no leader line extensions).
The
LLE
field inAnnotLine
hasthis should be >= 0 - particularly because the default is 0! It's non-negative.