I found this code.
static void rescan_forest_trusts( void )
/* The only transitive trusts supported by Windows 2003 AD are
(a) Parent-Child, (b) Tree-Root, and (c) Forest. The
first two are handled in forest and listed by
DsEnumerateDomainTrusts(). Forest trusts are not so we
have to do that ourselves.
What I feel:
1. We should update the code comments for with "Windows 2016" trust support, If supported.
2. Or we should make this as generic statement.