in lru.go [561:571]
func (lru *LRU[K, V]) Keys() []K {
lru.PurgeExpired()
keys := make([]K, 0, lru.len)
pos := lru.elements[lru.head].next
for i := uint32(0); i < lru.len; i++ {
keys = append(keys, lru.elements[pos].key)
pos = lru.elements[pos].next
}
return keys
}