Mind that Spring's Cache isn't generic thus no

<>

, or

<K, V>

are allowed after

: Cache

. For instance you could extend a generic one this way:

interface Cache<K, V> : javax.cache.Cache<K,V> { ... }

by the way, what does this means

registrar: (key: K) -> V?)

In the following function

fun getOrPut(key: K, fun getOrPut(key: K, registrar: (key: K) -> V?): V?: V?

i thinks

registrar

is something likes the arguments name, so what are the rest? is it a lambda ?