A node's property branches, keyed by property name.
Each name maps to the one Branch reachable through it. A name declared by several variants of a
union-typed node is one property (union coherence, §3.2): its branch ranges over the disjunction of the
per-variant declarations (§5.8.1), carries every request reaching it folded into one drain,
and is entered through the first declaring variant's entry.
A node's property branches, keyed by property name.
Each name maps to the one Branch reachable through it. A name declared by several variants of a union-typed node is one property (union coherence, §3.2): its branch ranges over the disjunction of the per-variant declarations (§5.8.1), carries every request reaching it folded into one drain, and is entered through the first declaring variant's
entry.