Function claim_archetype 

pub(crate) fn claim_archetype(
    world: &World,
    group: u64,
    index: u32,
    archetype: &Archetype,
    asks: &[(TypeId, &'static str, Mode)],
    origin: &'static Location<'static>,
)

Claim on archetype every component the asks named, shared or exclusive.

Components the archetype does not carry are skipped: an optional item reaches nothing there, and claiming it anyway would refuse another query for no reason.