},
    {
        @Suppress("unchecked_cast")
        val comparator = read() as Comparator<Any?>?
        readMapInto { TreeMap(comparator) }
    }
)


fun <T : MutableMap<Any?, Any?>> mapCodec(factory: (Int) -> T): Codec<T> = codec(
    { writeMap(it) },
    { readMapInto(factory) }

suspend fun WriteContext.writeMapEntries(value: Map<*, *>) {
    for (entry in value.entries) {
        write(entry.key)
        write(entry.value)
    }
}


suspend fun <T : MutableMap<Any?, Any?>> ReadContext.readMapInto(factory: (Int) -> T): T {
    val size = readSmallInt()
    val items = factory(size)
    readMapEntriesInto(items, size)
    return items
}