Three-valued because the caller's responses to a missing node are opposites: it waits for one that
is merely late and fails fast on one that is absent. absent is therefore reserved for a store
that actually answered — an unreachable edge or an unparseable id is unknown.
What a NavigationTargetLoader was able to determine about a target.
Three-valued because the caller's responses to a missing node are opposites: it waits for one that is merely late and fails fast on one that is absent.
absentis therefore reserved for a store that actually answered — an unreachable edge or an unparseable id isunknown.