Map<PsiElement, Cardinality> map = psiMap();
boolean leftMarker = m.containsKey(LEFT_MARKER);
for (PsiElement t : m.keySet()) {
Cardinality joinedCard = fromNodeType(type).and(m.get(t));
if (leftMarker) {
joinedCard = joinedCard.single();
}
map.put(t, joinedCard);
}
return map;
}